Digital video system

ABSTRACT

The erasion level appending range of a file is instructed. According to this instruction, the erasion level is set. When this setting range does not agree with the cell unit of the current cell, the current cell is divided to set a sequence of divided cells. Playback management information of each of the divided cells and current cell is re-created, and erasion level information is appended to playback management information of the divided cell that belongs to the appending range.

TECHNICAL FIELD

[0001] The present invention relates to a digital video system(apparatus and method) capable of real-time recording, and aninformation recording medium (recordable optical disc) used in thissystem.

BACKGROUND ART

[0002] In recent years, systems for playing back the contents of opticaldiscs such as video CDs that record video data, audio data, and the likehave been developed, and have prevailed for the purpose of playing backmovie software titles, karaoke data, and the like.

[0003] Among such systems, a DVD (Digital Versatile Disc) standard thatuses MPEG2 (Moving Picture Experts Group 2) international standards hasbeen proposed.

[0004] This standard supports MPEG2 as a moving picture compressionscheme, and AC-3 audio, MPEG audio, and the like as audio schemes. Thestandard is appended with sub-picture data for superimposed dialogs andmenus obtained by compressing bitmap data, and control data (navigationdata) for special playback control. Furthermore, this standard supportsthe UDF (Universal Disc Format) Bridge (a hybrid of UDF and ISO9660) toallow a computer to read data.

[0005] Also, optical discs such as a DVD-RAM and the like on whichdigital data can be written or rewritten have been developed. A functionthat allows one to easily edit the recorded contents is required of adigital video system using such DVD-RAM or the like.

[0006] However, a home-use digital video system which allows end-usersto easily edit the recorded contents has not become available yet.

DISCLOSURE OF INVENTION

[0007] It is an object of the present invention to provide a digitalvideo system (apparatus and method) which allows easy and flexibleediting.

[0008] It is another object of the present invention to provide aninformation recording medium (recordable optical disc) which allowsefficient data management, and can manage save units finely.

[0009] In order to achieve the above objects, the digital video systemof the present invention uses a data area for storing file datacontaining digital movie information recorded in a predeterminedrecording unit; and a management area for storing navigation data formanaging information stored in the data area. In this system themanagement area includes a storage field for storing an erasion levelflag which sets a specific recording unit in the data area in atemporarily erased state.

BRIEF DESCRIPTION OF DRAWINGS

[0010]FIG. 1 is a perspective view for explaining the structure of arecordable optical disc according to an embodiment of the presentinvention;

[0011]FIG. 2 is a view for explaining an example of the logicalstructure of information recorded on the optical disc shown in FIG. 1;

[0012]FIG. 3 is a view for explaining an example of the directorystructure of information (data files) recorded on the optical disc shownin FIG. 1;

[0013]FIG. 4 is a view for explaining an example of the hierarchicalstructure of a video object set (VTS) shown in FIG. 2;

[0014]FIG. 5 is a view for explaining the contents of packs in thelowermost layer of the hierarchical structure shown in FIG. 4;

[0015]FIG. 6 is a view for explaining the contents of presentationcontrol information (PCI) shown-in FIG. 5;

[0016]FIG. 7 is a view for explaining the contents of presentationcontrol information general information (PCI_GI) shown in FIG. 6;

[0017]FIG. 8 is a view for explaining the contents of video title setinformation (VTSI) shown in FIG. 2;

[0018]FIG. 9 is a view for explaining the contents of a video title setprogram chain information table (VTS_PGCIT) shown in FIG. 8;

[0019]FIG. 10 is a view for explaining the contents of program chaininformation (PCGI) shown in FIG. 9;

[0020]FIG. 11 is a view for explaining the contents of a cell playbackinformation table (C_PBIT) shown in FIG. 10;

[0021]FIG. 12 is a view for explaining the contents of cell playbackinformation (C_PBI) shown in FIG. 11;

[0022]FIG. 13 is a view for explaining the contents of a cell category(C_CAT) shown in FIG. 12;

[0023]FIG. 14 is a view for explaining the contents of program chaingeneral information (PGC_GI) for normal PGC;

[0024]FIG. 15 is a view for explaining the contents of program chaingeneral information (PGC_GI) for trash PGC;

[0025]FIG. 16 is a view for explaining the contents of cell playbackinformation (C_PBI) for trash PGC;

[0026]FIG. 17 is a view for explaining the format of digital informationrecorded on the optical disc shown in FIG. 1;

[0027]FIG. 18 is a view for explaining the data structure of a videoobject unit (VOB) shown in FIG. 17;

[0028]FIG. 19 is a view for explaining the data structure of a dummypack shown in FIG. 18;

[0029]FIG. 20 is a view for explaining the file structure of digitalinformation recorded on the optical disc shown in FIG. 1;

[0030]FIG. 21 is a view for explaining the data structure of anavigation data file (RTR_VMG) shown in FIG. 20;

[0031]FIG. 22 is a view for explaining the contents of a video managerinformation table (VMGI_MAT) shown in FIG. 21;

[0032]FIG. 23 is a view for explaining the data structure of a movie AVfile information table (M_AVFIT) shown in FIG. 21;

[0033]FIG. 24 is a view for explaining the data structure of movie VOBinformation (M_VOBI) shown in FIG. 23;

[0034]FIG. 25 is a view for explaining the data structure of time mapinformation (TMAPI) shown in FIG. 24;

[0035]FIG. 26 is a view for explaining the data structure of a userdefined PGC information table (UD_PGCIT) shown in FIG. 21;

[0036]FIG. 27 is a view for explaining the data structure of PGCinformation (PGCI; information of an original PGC or user defined PGC);

[0037]FIG. 28 is a view for explaining the contents of PGC generalinformation (PGC_GI) shown in FIG. 27;

[0038]FIG. 29 is a view for explaining the contents of programinformation (PGI) shown in FIG. 27;

[0039]FIG. 30 is a view for explaining the data structure of cellinformation (CI) shown in FIG. 27;

[0040]FIG. 31 is a view for explaining the data structure of movie cellinformation (M_CI) shown in FIG. 30;

[0041]FIG. 32 is a view for explaining the contents of movie cellgeneral information (M_C_C_GI) shown in FIG. 31;

[0042]FIG. 33 is a view for explaining the contents of movie cell entrypoint information (M_C_EPI) shown in FIG. 31;

[0043]FIG. 34 is a block diagram showing an example of the arrangementof an apparatus for recording/playing back a video program or the likein real time (RTR video recorder) using the recordable optical discshown in FIG. 1;

[0044]FIG. 35 is a flow chart for explaining recording in the apparatusshown in FIG. 34;

[0045]FIG. 36 is a flow chart for explaining an erasion level setupprocess;

[0046]FIG. 37 is a flow chart continued from FIG. 36;

[0047]FIG. 38 is a view for explaining examples of windows displayedupon setting the erasion level;

[0048]FIG. 39 is a view for explaining cell division;

[0049]FIG. 40 is a flow chart for explaining recovery (restoration) andactual erasion of a cell in which an erasion level flag is set;

[0050]FIG. 41 is a view for explaining examples of windows displayedupon recovering (restoring) and actually erasing a cell in which anerasion level flag is set;

[0051]FIG. 42 is a flow chart for explaining automatic erasion of a cellin which an erasion level flag is set;

[0052]FIG. 43 is a view for explaining example of windows displayed uponerasing a cell in which an erasion level flag is set;

[0053]FIG. 44 is a flow chart for explaining the playback process of theapparatus shown in FIG. 34;

[0054]FIGS. 45-48 are a set of flow charts explaining a manner ofdividing VOB and cell;

[0055]FIG. 49 explains a manner of dividing cells where one cell isequal to one VOB; and

[0056]FIG. 50 explains a manner of dividing VOBs where one cell is notequal to one VOB.

BEST MODE OF CARRYING OUT THE INVENTION

[0057] Preferred embodiments of the present invention will be describedhereinafter with reference to the accompanying drawings. In thisdescription, the same reference numerals and symbols denote illustratedcomponents having common functions throughout the figures, and arepetitive description thereof will be avoided.

[0058]FIG. 1 is a view for explaining the structure of a recordableoptical disc according to an embodiment of the present invention. FIG. 1also shows the correspondence between the data recording area of opticaldisc 10 (DVD-RAM or the like), and data recording tracks recorded there.

[0059] The physical structure of the optical disc will be explainedfirst.

[0060] Referring to FIG. 1, optical disc 10 has a structure obtained byadhering a pair of transparent substrates 14 each having recordablelayer 17 (one or two layers) using adhesive layer 20. Each substrate 14is formed of a 0.6-mm thick polycarbonate film, and adhesive layer 20consists of an ultraviolet setting resin having a thickness of 40 μm to70 μm. When the pair of substrates 14 are adhered to each other so thattheir recordable layers 17 contact each other on the surfaces ofadhesive layer 20, a 1.2-mm thick large-capacity optical disc 10 isobtained.

[0061] Reference numeral 22 denotes a center hole; and 24, a clamp area.Reference numeral 25 denotes an information area; 26, a lead-out area;27, a lead-in area; and 28, a data recording area. On recordable layer17 of information area 25, a recording track is continuously formed in,e.g., a spiral pattern. The continuous track is divided into a pluralityof physical sectors, which have serial numbers and are used as recordingunits.

[0062] Referring to FIG. 1, when disc 10 is a rewritable DVD-RAM/DVD-RW(or write once DVD-R), this disc is housed in a cartridge. When thecartridge that houses DVD-RAM disc 10 is loaded into a discrecording/playback apparatus (DVD video recorder or DVD video player),and is extracted, disc 10 alone remains in the apparatus.

[0063] The data recording track of recordable layer 17 is divided into aplurality of logical sectors (minimum recording units) each having agiven storage capacity, and data are recorded with reference to theselogical sectors. The recording capacity per logical sector is determinedto be 2,048 bytes which are equal to one pack data length.

[0064]FIG. 2 is a view for explaining an example of the logicalstructure of information recorded on the optical disc shown in FIG. 1.

[0065] Information area 25 shown in FIG. 1 can have a structure shownin, e.g., FIG. 2. The logical format of this structure is defined tocomply with, e.g., the Universal Disc Format (UDF) Bridge (a hybrid ofUDF and ISO9660) as one of standard formats.

[0066] Referring to FIG. 2, data recording area 28 is assigned as avolume space. Volume space 28 includes space (volume/file structure) 70for information of the volume and file structures, space (DVD videoarea) 71 for applications compatible with the DVD specifications, andspace (other recording area) 73 for applications compatible withspecifications other than the DVD specifications.

[0067] Volume space 28 is physically divided into a large number ofsectors, which have serial numbers. The logical addresses of datarecorded on this volume space 28 mean logical sector numbers, asspecified by the UDF Bridge. The logical sector size in this space is2,048 bytes as in the physical sector size. The logical sector numbersare assigned serial numbers in ascending order of physical sectornumber. Note that each physical sector is appended with error correctioninformation and the like unlike logical sectors.

[0068] Volume space 28 has a hierarchical structure, which includesvolume/file structure area 70, DVD video area 71 consisting of one ormore video title sets VTS#n 72, and other recording area 73. These areasare split up on the boundaries of logical sectors. Note that one logicalsector is defined to be 2,048 bytes, and one logical block is alsodefined to be 2,048 bytes. Hence, one logical sector is definedequivalently with one logical block.

[0069] Volume/file structure area 70 corresponds to a management areadefined by the UDF Bridge. Based on the description of this area 70, thecontents of video manager VMG are stored in an internal system memory(not shown) of the apparatus.

[0070] DVD video area 71 is constructed by file 74A containing one ormore video title sets VTS 72, and video manager VMG for managing theseVTS. Note that VMG contains video manager information VMGI, video objectset VMGM_VOBS for manager menus, and backup file VMGI_BUP of VMGI, asneeded.

[0071] Each VTS 72 is constructed by file 74B that contains video objectset VTSM_VOBS for video title set menus, video object set VTSTT_VOBS forvideo title set titles, video title set information VTSI for managingVTSTT_VOBS, and backup file VTSI_BUP of VTSI, as needed.

[0072] Other recording area 73 can record information that can be usedin VTS mentioned above or other kinds of information that are irrelevantto VTS.

[0073] Note that VTSTT_VOBS defines a set of one or more video objectsVOB. Each VOB defines a set of one or more cells. A set of one or morecells make up program chain PGC. Assuming that one PGC corresponds toone drama, a plurality of cells that make up this PGC can correspond tovarious scenes in that drama.

[0074] When volume space 28 of single disc 10 stores a plurality ofvideo title sets VTS#n, the structure shown in FIG. 2 is suitably used.However, when volume space 28 of single disc 10 stores only one videotitle set VTS, another structure may be used. An example of suchstructure will be described later with reference to FIG. 17. In thisstructure, file 74A shown in FIG. 2 is omitted, and a file similar tofile 74B is stored in the data area of DVD video area 71 instead.

[0075]FIG. 3 shows an example of the directory structure of information(data files) recorded on optical disc 10.

[0076] As shown in FIG. 3, the subdirectory of video title set VTS, thatof audio title set ATS, and the like are linked under the rootdirectory. Various video files (files VMGI, VMGM, VTSI, VTSM, VTS, andthe like) are contained in the subdirectory of VTS and managedsystematically. A specific file (e.g., specific VTS) can be accessed bydesignating the path from the root directory to that file.

[0077] DVD-RAM (DVD-RW) disc 10 or DVD-R disc 10 may be pre-formatted tohave the directory structure shown in FIG. 3 (or FIG. 20 to be describedlater), and pre-formatted discs 10 may be put on the market as unuseddiscs (raw discs) for DVD video recording.

[0078] That is, the root directory of pre-formatted raw disc 10 includesa subdirectory named VTS (or DVD_RTR shown in FIG. 20). Thissubdirectory can contain various management data files (VIDEO_TS.IFO,VTS_01_0. IFO shown in FIG. 3; RTR.IFO shown in FIG. 20); backup files(VIDEO_TS.BUP, VTS_01_0.BUP; backup files are omitted in FIG. 20) forbacking up information of these management data files; and video datafiles (VTS_01_.VOB and the like in FIG. 3; RTR_MOV.VRO and the like inFIG. 20) which are managed based on the contents of the management datafiles and store digital moving picture information.

[0079] The subdirectory (VTS directory in FIG. 3 or DVD_RTR directory inFIG. 20) can also contain menu data files (VMGM, VTSM) for storingpredetermined menu information, as needed.

[0080] On single disc 10, a file called video manager VMG is present asinformation (navigation data) for managing this disc. Furthermore, titleset.VTS contains a video title set information VTSI file (RTR.IFO incase of FIG. 20), video file, and backup file of VTSI.

[0081]FIG. 4 shows the hierarchical structure of information containedin video title set title video object set VTSTT_VOBS.

[0082] As shown in FIG. 4, video object set VTSTT_VOBS 82 is defined asa set of one or more video objects VOB 83. Each VOB 83 is made up of aset of one or more cells 84, each of which is, in turn, made up of a setof one or more video object units VOBU 85. Each VOBU is made up of a setof various data packs 86 to 91.

[0083] Each of these packs serves as a minimum unit of data transfer.The minimum unit for logical processing is a cell, and logicalprocessing is done is units of cells. (When the data structure shown inFIGS. 20 to 33 to be described later is used, processing which usesentry points that can be units smaller than cells can be done.)

[0084] The playback time of VOBU corresponds to that of video data madeup of one or more picture groups (groups of pictures GOP in MPEG), andis set to fall within the range from 0.4 sec to 1.2 sec. One GOP isscreen data which normally has a playback time of about 0.5 sec in theMPEG format, and is compressed to play back approximately 15 imagesduring this interval. Note that even playback data consisting of audiodata and/or sub-picture data alone is formed using VOBU as one unit.

[0085] When a DVD video recorder can record VOBS with this structure(RTR_MOV.VRO in FIG. 20) on optical disc 10, the user often wants toedit the recording contents after recording. In order to meet suchrequirement, dummy packs can be appropriately inserted in each VOBU.Each dummy pack can be used to record edit data later.

[0086] VOBS for menus normally consists of one VOB, which stores aplurality of menu screen display data. By contrast, VOBS for title setsnormally consists of a plurality of VOBS.

[0087] VOB is assigned an identification number (IDN#i; i=0 to i), andthat VOB can be specified by the identification number. A normal videostream consists of a plurality of cells, but a menu video stream oftenconsists of a single cell. Each cell is assigned an identificationnumber (C_IDN#j) as in VOB.

[0088] As mentioned above, the video file (file 74A or 74B in FIG. 2)has a hierarchical structure, and one file is constructed by one or moreprogram chains PGC, each of which is, in turn, constructed by one ormore programs. One program is constructed by one or more cells, each ofwhich is, in turn, constructed by one or more video object units VOBU.Each VOBU is constructed by packs each containing a plurality of kindsof data, and each pack is constructed by one or more packets and a packheader.

[0089] Video object VOB corresponds to management data PGCI in units ofPCGs (this PGCI corresponds to ORG_PGCI in FIG. 21 or UD_PGCI in FIG. 26to be described later). PGCI stores cell playback information tableC_PBIT for managing cells, which are played back in the order describedin C_PBIT. Actual cell playback addresses are recorded as cell playbackinformation C_PBI (which corresponds to CI in FIG. 27 to be describedlater) in C_PBIT.

[0090] In the embodiment of the present invention, managementinformation for PGC and that for cells can be independent from eachother.

[0091]FIG. 5 shows an example of the contents of packs in the lowermostlayer of the hierarchical structure shown in FIG. 4. This pack sequenceincludes navigation pack 86, video packs 88, dummy packs 89, sub-picturepacks 90, audio packs 91, and the like.

[0092] Navigation pack 86 includes pack header 110, playback controlinformation/presentation control information (PCI) packet 116, and datasearch information (DSI) packet 117. PCI packet 116 is made up of packetheader 112 and PCI data 113, and DSI packet 117 of packet header 114 andDSI data 115.

[0093] PCI packet 116 contains control data used upon, e.g.,non-seamlessly switching the playback angles. DSI packet 117 containscontrol data used upon, e.g., seamlessly switching the playback angles.Note that the “angle switching” means changes in angle (camera angle) inwhich the object picture is watched.

[0094] When the structure shown in FIGS. 17 and 18 to be described lateris used, navigation pack 86 is not used, and navigation data RTR_VMGshown in FIG. 20 is used instead.

[0095] Video pack 88 is comprised of pack header 881 and video packet882. The dummy pack is comprised of pack header 891 and padding packet890, and padding packet 890 of packet header 892 and padding data 893.Note that padding data 893 stores insignificant data.

[0096] Sub-picture pack 90 is made up of pack header 901 and sub-picturepacket 902. The audio pack is made up of pack header 911 and audiopacket 912.

[0097] Note that video packet 882 contains a packet header (not shown),which records a decode time stamp (DST) and presentation time stamp(PTS). Each of sub-picture packet 902 and audio packet 912 contains apacket header (not shown), which records a presentation time stamp(PTS).

[0098]FIG. 6 shows the contents of the presentation control information(PCI data 113) shown in FIG. 5.

[0099] The PCI data includes PCI general information (PCI_GI),non-seamless playback angle information (NSML_AGLI), highlightinformation (HLI), and recording information (RECI). This recordinginformation (RECI) can contain a copyright management code (ISRC) of theinternational standard.

[0100]FIG. 7 shows the contents of the presentation control informationgeneral information (PCI_GI) shown in FIG. 6.

[0101] Presentation control information general information PCI_GIdescribes the logical block number (NV_PCK_LBN) of a navigation pack,the category (VOBU_CAT) of VOBU, user operation control (VOBU_UOP_CTL)of VOBU, the start presentation time (VOBU_S_PTM) of VOBU, the endpresentation time (VOBU_E_PTM) of VOBU, the end presentation time(VOBU_SE_PTM) of the sequence end in VOBU, and a cell elapse time(C_ELTM).

[0102] Note that the logical block number (NV_PCK_LBN) represents theaddress (recording location) of a navigation pack including thepresentation control information (PCI) by the relative number of blocksfrom the first logical block in the video object set (VOBS) whichincludes that PCI.

[0103] VOBU_CAT describes the contents of copy protection of an analogsignal corresponding to video and sub-picture data in VOBU that includesthe presentation control information (PCI). VOBU_UOP_CTL describes useroperations which are prohibited during the display .(presentation)period of VOBU that includes the presentation control information (PCI).VOBU_S_PTM describes the start time of display (presentation) of VOBUthat includes the presentation control information (PCI). Morespecifically, this VOBU_S_PTM indicates the start display time of thefirst video (first picture) in the display order of the first GOP inVOBU.

[0104] VOBU_E_PTM describes the end time of display (presentation) ofVOBU that includes the presentation control information (PCI). Morespecifically, this VOBU_E_PTM indicates the end display time of the lastvideo (last picture) in the display order of the last GOP in VOBU.

[0105] On the other hand, when no video data is present in VOBU, or whenplayback of that VOBU is stopped, this VOBU_E_PTM indicates the end timeof virtual video data aligned to time grids of field intervals({fraction (1/60)} sec in case of NTSC video).

[0106] VOBU_SE_PTM describes the end time of display (presentation)based on a sequence end code in video data in VOBU that includes thepresentation control information (PCI). More specifically, this end timeindicates the end display time of the last video (last picture) in thedisplay order, which picture includes the sequence end code, in VOBU. Ifno video (picture) with a sequence end code is present in VOBU, 00000000h (h is an abbreviation for hexadecimal) is set in VOBU_SE_PTM.

[0107] C_ELTM describes the relative display (presentation) time fromthe first video frame in the display order of a cell that includes thepresentation control information (PCI) to the first video frame in thedisplay order of VOBU that includes the PCI in hours, minutes, andseconds in the BCD format and frames. When no video data is present inVOBU, the first video frame of the virtual video data is used as thevideo frame.

[0108]FIG. 8 shows the contents of the video title set information(VTSI) shown in FIG. 2.

[0109] This VTS consists of a plurality of files. Each file containsvideo title set information (VTSI), object set (VTSM_VOBS) for videotitle set menus, video object sets (VTSTT_VOBS) for video title settitles, and backup information (VTSI_BUP) for video title setinformation.

[0110] VTSI set at the beginning of VTS describes a video title setinformation management table (VTSI_MAT), a title search pointer table(VTS_PTT_SRPT) for a VTS part_of_title (e.g., chapter of a program), aVTS program chain information table (VTS_PGCIT), a VTS menu PGCinformation unit table (VTSM_PGCI_UT), a VTS time map table (VTS_TMAPT),a VTS menu cell address table (VTSM_C_ADT), a VTS menu VOBU address map(VTSM_VOBU_ADMAP), a VTS cell address table (VTS_C_ADT), and a VTS VOBUaddress map (VTS_VOBU_ADMAP) in this order.

[0111] The contents of video title set information management tableVTSI_MAT (corresponding to VMGI_MAT shown in FIG. 22 to be describedlater) are as follows.

[0112] More specifically, VTSI_MAT describes a VTS identifier, the endaddress of VTS, a played back flag indicating whether or not a programrecorded on optical disc 10 has been completely played back at leastonce, an archive flag (ARCHIVE_FLAG; this flag may be omitted, andreplaced by a flag in units of cells, as will be described later) whichserves to prevent erase errors when a program recorded on optical disc10 is to be kept without being erased, the end address of VTSI, theformat that this optical disc 10 uses and its version number, a VTScategory, the end address of VTSI_MAT, the start address of VTS menuVOBS, and the start address of VTSTT_VOBS.

[0113] Furthermore, VTSI_MAT describes the start address(VTS_PTT_SRPT_SA) of the part_of_title search pointer table to allow asearch for part of VTS, the start address (VTS_PGCIT_SA) of the PGCinformation table that sets the playback order of VTS, the start address(VTSM_PGCI_UT_SA) of the PGC information unit table for VTS menu displaycontrol, the start address (VTS_TMAST_SA) of the time map tableindicating the elapse time of VTS, the start address (VTSM_C_ADT_SA) ofthe cell address table of cells used for VTS menu display, the startaddress (VTSM_VOBU_ADMAP_SA) of the VOBU address map for VTS menudisplay, the start address (VTS_C_ADT_SA) of the VTS cell address table,the start address (VTS_VOBU_ADMAP_SA) of the VTS VOBU address map,information of attributes of video data, audio data, sub-picture data,and the like, the number of sub-picture streams of VTS, a sub-picturestream attribute table of VTS, and a multichannel audio stream attributetable of VTS.

[0114]FIG. 9 shows the contents of the video title set program chaininformation table (VTS_PGCIT) shown in FIG. 8.

[0115] This VTS_PGCIT contains VTS program chain information tableinformation (VTS_PGCITI), VTS program chain information search pointers(VTS_PGCI_SRP#1 to VTS_PGCI_SRP#n), and VTS program chain information(VTS_PGCI).

[0116] Note that the order of a plurality of pieces of informationVTS_PGCI is set independently of that of the plurality of VTS programchain information search pointers VTS_PGCI_SRP#1 to VTS_PGCI_SRP#n.Hence, for example, single program chain information VTS_PGCI can beindicated by one or more program chain information search pointersVTS_PGCI_SRP.

[0117]FIG. 10 shows the contents of the program chain information (PGCI)shown in FIG. 9.

[0118] PGCI is made up of PGC general information (PGC_GI), a PGCcommand table (PGC_CMDT), a PGC program map (PGC_PGMAP), cell playbackinformation table (C_PBIT), and cell position information table(C_POSIT).

[0119]FIG. 11 shows the contents of the cell playback information table(C_PBIT) shown in FIG. 10.

[0120] This cell playback information table C_PBIT can contain a maximumof 255 pieces of cell playback information (C_PBIn; #n=#1 to #255).

[0121] Note that cell playback information C_PBI used in the structureshown in FIG. 2 corresponds to cell information CI (FIGS. 27 and 30)used in the structure shown in FIG. 17 (to be described later).

[0122]FIG. 12 shows the contents of cell playback information C_PBI(C_PBI#1 to C_PBI#n) shown in FIG. 11.

[0123] More specifically, each C_PBI contains a cell category (C_CAT),cell playback time (C_PBTM), the start address (C_FVOBU_SA) of the firstvideo object unit (VOBU) in the cell, the end address (C_FILVU_EA) ofthe first interleaved unit (ILVU) in the cell, the start address(C_LVOBU_SA) of the last VOBU in the cell, and the end address(C_LVOBU_EA) of the last VOBU in the cell.

[0124] Furthermore, in this C_PBI, a 1-byte field (cell type) fordescribing an erasion level flag is assured.

[0125] When this erasion level flag is 00 h, a cell appended with thisflag can be played back (or not set in an erasion state), and this flagcan be used to mean prohibition of automatic erasion.

[0126] When the erasion level flag is 01 h, a cell appended with thisflag is prohibited from being played back (or set in an erasion state),and this flag can be used to mean permission of automatic erasion.

[0127] The contents corresponding to the cell erasion level flag shownin FIG. 12 can be described in primary text information PRM_TXTI shownin FIG. 33 (to be described later).

[0128]FIG. 13 shows the contents of the cell category (C_CAT) shown inFIG. 12.

[0129] This C_CAT indicates the number of cell commands by the lower 8bits; the cell still time by the next 8 bits (b8 to b15); the cell typewith contents different from that shown in FIG. 12 by the next 5 bits;an access restriction flag by the next 1 bit; the cell playback mode(e.g., movie or still) by the next 1 bit; a seamless angle change flagby 1 bit after the next reserved bit; a system time clock STCdiscontinuity flag (to reset STC or not) by the next 1 bit; aninterleaved allocation flag (indicating if the cell designated by C_PBIis located in a continuous block or an interleaved block) by the next 1bit; a seamless playback flag (indicating if the cell designated byC_PBI is to be played back seamlessly) by the next 1 bit; the cell blocktype (e.g., angle block) by the next two bits; and the cell block mode(e.g., first cell in the block) by the last two bits.

[0130] If the cell block mode bits are 00b (b means binary), this meansthat the cell is not the one in the block; if the bits are 01b, the cellis the first one in the block; if the bits are 10b, the cell is the onein the block; and if the bits are 11b, the cell is the last one in theblock.

[0131] If the cell block type bits are 00b , this indicates that thecell block does not belong to the corresponding block; and if the bitsare 01b, the corresponding block is an angle block (a block containingmultiangle cells).

[0132] On the other hand, if this cell block type=01b is detected duringplayback, the apparatus can inform the viewer that playback of the angleblock is currently in progress by flickering an angle mark (or bychanging the ON color or shape of the angle mark). With suchinformation, the viewer can make sure that an image in another angle isavailable for the picture which is currently being played back.

[0133] If the interleaved allocation flag is 0b, it indicates that thecorresponding cell belongs to a continuous block (that continuouslyrecords a plurality of VOBUs); if the interleaved allocation flag is 1b,the corresponding cell belongs to an interleaved block (thatinterleaved-records ILVUs each containing one or more VOBUs).

[0134] If the seamless angle change flag is set (=1b), it representsthat the corresponding cell is to be seamlessly played back; if thisflag is not set (=0b), the corresponding cell is to be non-seamlesslyplayed back.

[0135] That is, if the interleaved allocation flag=1b and seamless anglechange flag=0b, the angle can be changed non-seamlessly; if theinterleaved allocation flag=1b and seamless angle change flag=1b, theangle can be changed seamlessly.

[0136] If a media drive system with a very short access time (a systemthat can access the beginning of a desired angle block within one videoframe period; not limited to an optical disc drive system) is used, theangle can be changed smoothly even when the interleaved allocationflag=0b, i.e., between VOBU sets (different angle cells) which are notinterleaved-recorded.

[0137] When optical disc 10 with relatively low access speed is used asa recording medium, one recording track of that disc is preferablyassigned to recording of one interleaved block. In such format, sincethe trace destination of an optical head need only move in the radialdirection of the disc by a very small distance corresponding to onetrack width, track jump suffering less time lag (suitable for seamlessangle change) can be attained. In this case, if track jump for one videoobject unit (VOBU) is made, a time lag for a maximum of one revolutionof the disc may be produced. Hence, the angle change that requires jumpsin units of VOBUs is suitable for non-seamless angle change.

[0138] It is technically possible to design a DVD video recorder whichallows the viewer (user) to arbitrarily change the contents of theseamless angle change flag in read data after cell data of thecorresponding title set are read from an optical disc.

[0139] When the seamless angle change flag represents whether the angleinformation described in navigation pack 86 indicates seamless ornon-seamless angle information, if the user has changed this flag, he orshe must also modify angle information (not shown) in navigation pack 86(e.g., modification from seamless angle information to non-seamlessangle information).

[0140] When the cell playback mode is 0b, it indicates continuousplayback in the cell; if the mode is 1b, still playback in each VOBUpresent in the cell.

[0141] The access restriction flag can be used to prohibit directselection by user operation when the user makes recording, playback, andthe like. For example, when the access restriction flag of a cell thatrecords answers for a collection of questions is set (=1b), the user isprohibited from reading the answers by stealth.

[0142] The cell type in FIG. 13 with contents different from those ofthe cell type shown in FIG. 12 can indicate the following facts by its5-bit contents, for example, when the corresponding cell is formed forkaraoke.

[0143] If the 5 bits are 00000b , no cell type is designated; if the 5bits are 00001b, a title picture of the karaoke is designated; if the 5bits are 00010b, an introduction part of the karaoke is designated; ifthe 5 bits are 00011b, a song part other than a climax (bridge) part isdesignated; if the 5 bits are 00100b , a song part of the first climaxpart is designated; if the 5 bits are 00101b, a song part of the secondclimax part is designated; if the 5 bits are 00110b, a song part for amale vocal is designated; if the 5 bits are 00111b, a song part for afemale vocal is designated; if the 5 bits are 01000b, a song part formixed voices is designated; if the 5 bits are 01001b, an interlude part(instrumental part) is designated; if the 5 bits are 01010b, fading-inof the interlude part is designated; if the 5 bits are 01011b,fading-out of the interlude part is designated; if the 5 bits are01100b, the first ending part is designated; and if the 5 bits are01101b, the second ending part is designated. The contents of theremaining 5-bit code can be used for other purposes.

[0144] Note that the angle change can be applied to that for backgroundvideo data of the karaoke. (For example, a full-figure shot, closeupshots of the face and mouth, and the like of a singer who is singing aguide vocal can be angle-changed seamlessly along with the flow of akaraoke music or non-seamlessly by going back some bars, or duringrepeat playback between desired bars, whichever the viewer desires.)

[0145] On the other hand, if the 8-bit contents of the cell still timeare 00000000b, zero still time is designated; if the contents are11111111b, limitless still time is designated; if the contents fallwithin the range from 00000001b to 11111110b, a still display timehaving a duration defined by the decimal value (1to 254) designated bythe contents and expressed in seconds is designated. The number of cellcommands indicates the number of commands to be executed upon completionof playback of the corresponding cell.

[0146]FIG. 14 shows the contents of general information (PGC_GI) of anormal program chain (PGC).

[0147] More specifically, program chain general information PGC_GIdescribes PGC contents (PGC_CNT), a PGC playback time (PGC_PB_TM), PGCuser operation control information (PGC_UOP_CTL), a PGC audio streamcontrol table (PGC_AST_CTLT), a PGC sub-picture stream control table(PGC_SPST_CTLT), PGC navigation control information (PGC_NV_CTL), a PGCsub-picture palette (PGC_SP_PLT), the start address (PGC_CMDT_SA) of aPGC command table, the start address (PGC_PGMAP_SA) of a PGC programmap, the start address (C_PBIT_SA) of a playback information table ofcells in PGC, and the start address (C_POSIT_SA) of a positioninformation table of cells in PGC.

[0148] PGC_CNT indicates the number of programs and number of cells (amaximum of 255) in that PGC. In PGC having no video object VOB, thenumber of programs is “0”.

[0149] PGC_PB_TM represents the total playback time of programs in thatPGC in hours, minutes, seconds, and the number of video frames. ThisPGC_PB_TM also describes a flag (tc_flag) indicating the type of videoframe, and a frame rate (25 or 30 frames per sec) or the like isdesignated by the contents of this flag.

[0150] PGC_UOP_CTL indicates user operations prohibited in PGC which isbeing played back.

[0151] PGC_AST_CTLT can contain control information for each of eightaudio streams. Each control information includes a flag (availabilityflag) indicating if the corresponding audio stream is available in thatPGC, and conversion information from an audio stream number to thenumber of an audio stream to be decoded.

[0152] PGC_SPST_CTLT includes a flag (availability flag) indicating ifthat sub-picture stream is available in the corresponding PGC, andconversion information from a sub-picture stream number (32 numbers)into the number of a sub-picture stream to be decoded.

[0153] PGC_NV_CTL includes Next_PGCN indicating the number of PGC to beplayed back next after the PGC which is currently being played back,Previous_PGCN indicating the number (PGCN) of PGC quoted by a navigationcommand “LinkPrevPGC” or “PrevPGC_Search( )”, GoUp_PGCN indicating thenumber of PGC to which that PGC is to return, a PG Playback modeindicating the playback mode (sequential playback, random playback,shuffle playback, and the like) of the program, and a Still time valueindicating the still time after that PGC is played back.

[0154] PGC_SP_PLT describes 16 sets of luminance signals and two colordifference signals used in a sub-picture stream in that PGC.

[0155] PGC_CMDT_SA assures a description area for a pre-command executedbefore PGC playback, a post-command executed after PGC playback, and acell command executed after cell playback.

[0156] PGC_PGMAP_SA describes the start address of PGC_PGMAPrepresenting the program configuration in that PGC by a relative addressfrom the first byte of program chain information PGCI.

[0157] C_PBIT_SA describes the start address of cell playbackinformation table C_PBIT that determines the playback order of cells inthat PGC by a relative address from the first byte of PGCI.

[0158] C_POSIT_SA describes the start address of cell positioninformation table C_POSIT indicating VOB identification numbers and cellidentification numbers used in that PGC by a relative address from thefirst byte of PGCI.

[0159]FIG. 15 shows the contents of program chain general information(PGC_GI) of trash PGC that provides a “trash box” file for file erasion,and the like.

[0160] Trash PGC_GI shown in FIG. 15 is configured by adding a trash PGCflag (TRASH_PGC_FLG) to PGC_GI shown in FIG. 14.

[0161] If this trash PGC flag is 01h, it indicates that thecorresponding PGC is “trash PGC that pertains to playback of an erasedcell”. On the other hand, if this trash PGC flag is 00h, it indicatesthat the corresponding PGC is not “trash PGC” but a normal PGC.

[0162] Trash PGC_GI shown in FIG. 15 is PGC general information when PGCis built to permit playback of a cell, which is seemingly deleted(recording data remains undeleted in practice, but is prohibited frombeing played back by the erasion level flag), by inputting a specialkeyword (or by, e.g., mouse operation for dragging a file icon from atrash box icon).

[0163] In this case, the special keyword input for a specific cell inPGC with the trash PGC flag=01h (i.e., “trash box”) corresponds tooperation for restoring a video file (file icon) that has been throwninto the “trash box” file (trash icon) from the trash box.

[0164]FIG. 16 is a view for explaining the contents of cell playbackinformation (C_PBI) in trash PGC.

[0165] C_PBI of trash PGC shown in FIG. 16 has a configuration in whichthe cell type in C_PBI shown in FIG. 12 is replaced by PGC_N thatdesignates an original PGC number to which a cell that has been throwninto the trash box belongs, and C_IN_N for designating that cell number.

[0166] This C_PBI of trash PGC has no “erasion level flag” shown in FIG.12.

[0167] Cell playback information C_PBI shown in FIG. 16 is used forrestoring a “cell which is seemingly deleted” that belongs to PGC withthe trash PGC flag=01h in FIG. 15.

[0168] Management information (PGC_GI and C_PBI for trash PGC) forrestoring and playing back a “cell thrown into the trash box” shown inFIGS. 15 and 16 may be left in the internal memory of the apparatus (DVDvideo recorder) or may be written on disc 10 as hidden information whichis invisible to the user.

[0169]FIG. 17 is a view for explaining the format of digital informationrecorded on the optical disc shown in FIG. 1.

[0170] In this structure, lead-in area 27 includes an emboss data zonewhose light reflection surface has an embossed pattern, a mirror zonewhose surface is flat (mirror surface), and a rewritable zone capable ofinformation rewriting. Lead-out area 26 is also designed to be capableof information rewriting.

[0171] Data recording area (volume space) 28 is made up of volume/filemanagement (structure) information 70 and data area DA whose contentscan be rewritten by the user.

[0172] Volume/file management information 70 records file information ofaudio and video data recorded on data area DA, and information thatpertains to the whole volume.

[0173] Data area DA can randomly record areas DA1 and DA3 for recordingcomputer data, and video & audio data area DA2 for recording video/audiodata. Note that the recording order, recording information size, and thelike of computer data and video/audio data can be arbitrarilydetermined. Data area DA can record computer data or video/audio dataalone.

[0174] video & audio data area DA2 contains control information DA21,video object DA22, picture object DA23, and audio object DA24.

[0175] Control information DA21 can contain control information requiredupon executing various processes such as recording (image and/or audiorecording), playback, editing, search, and the like.

[0176] For example, control information DA21 can contain file RTR.IFO ofnavigation data RTR_VMG shown in FIG. 20 (to be described later).

[0177] Video object DA22 can contain information of the contents ofrecorded video data.

[0178] Picture object DA23 can contain still picture information ofstill pictures, slide pictures, and the like.

[0179] Audio object DA24 can contain information of the contents ofrecorded audio data.

[0180] Note that video object DA22 is made up of video object set VOBS.This VOBS has contents corresponding to one or more program chains PGC#1to PGC#k which respectively designate cell playback orders by differentmethods.

[0181] The emboss data zone of lead-in area 27 records the followinginformation in advance:

[0182] (1) the disk type such as a DVD-ROM, DVD-RAM (or DVD-RW), DVD-R,and the like; the disk size such as 12 cm, 8 cm, and the like; therecording density; and information that pertains to the entireinformation storage medium such as physical sector numbers indicatingthe recording start/end positions, and the like;

[0183] (2) the recording power and recording pulse width; the erasionpower; the playback power; information that pertains torecording/playback/erasion characteristics such as the linear velocityupon recording/erasion, and the like; and

[0184] (3) information that pertains to the manufacture of an individualinformation recording medium such as the manufacturing number, and thelike.

[0185] The rewritable zone of each of lead-in area 27 and lead-out area28 contains the following fields:

[0186] (4) a field for recording a unique disk name of each informationrecording medium;

[0187] (5) a test recording field (for confirming recording/erasionconditions); and

[0188] (6) a field for recording management information that pertains toa defective field in data area DA.

[0189] A DVD-RTR recorder/player (RTR video recorder or personalcomputer with a DVD-RAM drive) can record data in fields (4) to (6).

[0190] When disc 10 is set in a DVD-RTR recorder/player (RTR videorecorder), information in lead-in area 27 is read. Lead-in area recordsa predetermined reference code and control data in ascending order ofsector number.

[0191] The reference code in lead-in area 27 consists of two errorcorrection code blocks.(ECC blocks). Each ECC block has 16 sectors.These two ECC blocks (32 sectors) are generated by appending scrambledata. Upon playing back the reference code appended with the scrambledata, file operation or the like on the playback side is done to playback a specific data. symbol (e.g., 172) to assure the subsequent dataread precision.

[0192] Control data in lead-in area 27 is made up of 192 ECC blocks. Inthis control data field, the contents for 16 sectors in the respectiveblocks are repetitively recorded 192 times.

[0193] This control data consisting of 16 sectors contains physicalformat information in the first sector (2,048 bytes), and discmanufacturing information and contents provider information in thesubsequent sectors.

[0194] The physical format information contained in the control data hasthe following contents.

[0195] That is, the first location describes the version of the DVDspecifications the recording information complies with.

[0196] The second location describes the size (12 cm, 8 cm, or the like)of the recording medium (optical disc 10) and minimum read rate. In caseof read-only DVD video, 2.52 Mbps, 5.04 Mbps, and 10.08 Mbps arespecified as minimum read rates, and other minimum read rates arereserved. For example, when image recording is done at an average bitrate of 2 Mbps by an RTR video recorder capable of variable bit-raterecording, the minimum read rate can be set at 1.5 to 1.8 Mbps using thereserved field.

[0197] The third location describes the disc structure (the number ofrecordable layers, track pitch, type of recordable layer, and the likeof the recording medium (optical disc 10). Based on the type ofrecordable layer, it can be identified if that disc 10 is a DVD-ROM,DVD-R, or DVD-RAM (DVD-RW).

[0198] The fourth location describes the recording density (lineardensity and track density) of the recording medium (optical disc 10).The linear density indicates the recording length per bit (0.267 μm/bit,0.293 μm/bit, or the like). The track density indicates the spacingbetween neighboring tracks (0.74 μm/track, (0.80 μm/track, or the like).The fourth location includes a reserved field to designate othernumerical values as linear and track densities for a DVD-RAM or DVD-R.

[0199] The fifth location describes the start and end sector numbers andthe like of data area 28 of the recording medium (optical disc 10).

[0200] The sixth location describes a burst cutting area (BCA)descriptor. This BCA is applied to only a DVD-ROM disc as an option, andis an area for storing recording information after completion of thedisc manufacturing process.

[0201] The seventh location describes a free space of the recordingmedium (optical disc 10). For example, when disc 10 is a single-sided,single-layered recording DVD-RAM disc, information indicating 2.6 GB (orthe number of sectors corresponding to this number of bytes) isdescribed at this location of disc 10. When disc 10 is a double-sidedrecording DVD-RAM disc, information indicating 5.2 GB (or the number ofsectors corresponding to this number of bytes) is described at thatlocation.

[0202] Other locations are reserved for future use.

[0203]FIG. 18 is a view for explaining the data structure of the videoobject unit (VOB) shown in FIG. 17.

[0204] As shown in FIG. 18, each cell (e.g., cell #m) that forms videoobject DA22 consists of one or more video object units (VOBU). Each VOBUis formed as a set (pack sequence) of video packs, sub-picture packs,audio packs, dummy packs, and the like.

[0205] Each of these packs has a predetermined size, i.e., 2,048 bytes,and serves as a minimum unit upon transferring data.

[0206] The playback time of VOBU corresponds to that of video data madeup of one or more picture groups (GOP), and is set to fall within therange from 0.4 sec to 1.2 sec. One GOP is screen data which normally hasa playback time of about 0.5 sec in the MPEG format, and is compressedto play back approximately 15 images during this interval. (VOBUcontains an integer number of GOPS, except for a special case wherein agap is formed in the flow of video data. That is, VOBU is a videoinformation compression unit synchronous with GOPs.)

[0207] When VOBU contains video data, a video data stream is formed bylining up GOPs (complying with the MPEG format) each consisting of videopacks, sub-picture packs, audio packs, and the like. However, VOBU isdetermined with reference to the playback time of GOPs independently ofthe number of GOPs.

[0208] Note that even playback data consisting of audio data and/orsub-picture data alone is formed using VOBU as one unit. For example,when VOBU is formed by audio packs alone, audio packs to be played backwithin the playback time of the VOBU to which that audio data belongsare stored in that VOBU like in a video object of video data.

[0209] The packs that form each VOBU have similar data structures exceptfor a dummy pack. An audio pack will be taken as an example. As shown inFIG. 18, a pack header is allocated at the beginning of the pack, apacket header and sub-stream ID follow, and audio data is allocated atthe end of the pack. In such pack format, the packet header is writtenwith information of presentation time stamp PTS indicating the starttime of the first frame in the packet.

[0210] On the other hand, a video pack has a data structure obtained byexcluding the sub-stream ID from the audio pack shown in FIG. 18 (notethat the start video pack in VOBU has a predetermined system headerbetween the pack and packet headers).

[0211] In a DVD-RTR recorder/player that can record a video program thatcontains video object DA22 with the structure shown in FIG. 18 onoptical disc 10, the user often wants to edit the recording contentsafter recording. In order to meet such requirement, dummy packs can beappropriately inserted in each VOBU. Each dummy pack can be used torecord edit data later.

[0212] The dummy pack shown in FIG. 18 shows a data structure shown inFIG. 19.

[0213] More specifically, one dummy pack 89 is comprised of pack header891, packet header 892 having a predetermined stream ID, and paddingdata 893 padded with a predetermined code (insignificant data). Notethat packet header 892 and padding data 893 form padding packet 890. Thecontents of padding data 893 in a non-used dummy pack are not especiallysignificant.

[0214] This dummy pack 89 can be appropriately used when the recordingcontents are to be edited after predetermined image recording is done ondisc 10 shown in FIG. 1, and in other cases (for example, the dummy packis used as an audio pack that stores audio information of afterrecording).

[0215] More specifically, the dummy pack is inserted into each VOBU forthe purposes of:

[0216] addition of information to be additionally recorded after imagerecording (for example, memo information indicating that after-recordinginformation is inserted into an audio pack and replaced by a dummy packis inserted as sub-picture information into a sub-picture pack and isreplaced by a dummy pack);

[0217] compensation of a short size from an integer multiple of 32kbytes to match the VOBU size with an integer multiple of the ECC blocksize (32 kbytes); and so forth.

[0218] Also, the dummy pack can be used to store reduced-scale image.(thumbnail picture) data which is displayed on a user menu, as needed.

[0219]FIG. 20 is a view for explaining an example of the directorystructure of information (data files) recorded on the optical disc shownin FIG. 1 to have the data structure shown in FIG. 17.

[0220] According to the DVD-RTR specifications capable of digitalrecording/playback of a video picture in real time, the contents of aDVD-RTR disc are managed using the directory structure shown in FIG. 20,and are saved in accordance with a file system such as ISO9660, UDF, orthe like. (RTR is an abbreviation for real time recording.)

[0221] Even when the data structure shown in FIG. 17 is used on thedisc/apparatus side, this data structure is invisible to the user. Thedata structure that the user can actually see is a hierarchical filestructure shown in FIG. 20.

[0222] More specifically, directories such as a DVD_RTR directory,VIDEO_TS directory, AUDIO_TS directory, computer data file directories,and the like are displayed on the display screen (not shown) of the rootdirectory by means of menu windows, icons, or the like in correspondencewith the types of data recorded on data area DA shown in FIG. 17.

[0223] The DVD_RTR directory shown in FIG. 20 stores file RTR.IFO ofnavigation data RTR_VMG, file RTR_MOV.VRO of movie video objectRTR_MOV.VOB., file RTR_STO.VRO of still picture video objectRTR_STO.VOB, file RTR_STA.VRO of additional audio object RTR_STA.VOB forstill pictures, and the like.

[0224] Note that file RTR.IFO stores management information such as aprogram set, program, entry point, play list, and the like for managingmoving picture information.

[0225] File RTR_MOV.VRO stores recorded moving picture information andits audio information, file RTR_STO.VRO stores recorded still pictureinformation and its audio information, and file RTR_STA.VRO storesafter-recording data for a still picture, and the like.

[0226] When a DVD-RTR recorder/player (RTR video recorder) has afunction of displaying the directories shown in FIG. 20 and also has aplayback function of a DVD video disc (ROM disc), and the DVD video discis set in its disc drive, the VIDEO_TS directory shown in FIG. 20 isactivated. In this case, when the VIDEO_TS directory is opened, therecording contents of the set disc are further displayed.

[0227] When the DVD-RTR recorder/player has a DVD audio playbackfunction and a DVD audio disc is set in its disc drive, the AUDIO_TSdirectory shown in FIG. 20 is activated. In this case, when the AUDIO_TSdirectory is opened, the recording contents of the set disc are furtherdisplayed.

[0228] Furthermore, when the DVD-RTR recorder/player comprises apersonal computer with a DVD-RAM drive and has a computer dataprocessing function, and a DVD-RAM (or DVD-ROM) disc that has recordedcomputer data is set in that disc drive, the computer data directoryshown in FIG. 20 is activated. In this case, when the computer datadirectory is opened, the recording contents of the set disc are furtherdisplayed.

[0229] The user can access the recorded sources of DVD video source, DVDvideo ROM, DVD audio, and computer data (including computer programs) asif he or she were operating a personal computer, while observing a menuscreen or window display screen displayed with the directory structureshown in FIG. 20.

[0230]FIG. 21 is a view for explaining the data structure of thenavigation data file (RTR_VMG) shown in FIG. 20. RTR video managerRTR_VMG as navigation data is comprised of various kinds of information,as shown in FIG. 21.

[0231] Referring to FIG. 21, RTR video manager information RTR_VMGIdescribes basic information of recordable optical disc (RTR disc) 10shown in FIG. 1. This RTR_VMGI contains video manager informationmanagement table VMGI_MAT and play list search pointer table PL_SRTP.

[0232] RTR_VMGI further contains movie AV file information tableM_AVFIT, still picture AV file information table S_AVFIT, original PGCinformation ORG_PGCI, user defined PGC information table UD_PGCIT, textdata manager TXTDT_MG, and manufacturer's information table MNFIT.

[0233]FIG. 22 shows the contents of the video manager informationmanagement table (VMGI_MAT) shown in FIG. 21.

[0234] Referring to FIG. 22, VMG identifier VMG_ID describes“DVD_RTR_VMG0” that specifies an RTR_VMG file using an ISO646 characterset code.

[0235] RTR_VMG_EA describes the end address of RTR_VMG by a relativebyte number from the first byte of RTR_VMG.

[0236] VMGI_EA describes the end address of RTR_VMGI by a relative bytenumber from the first byte of RTR_VMG.

[0237] VERN describes the version number of the DVD specifications forvideo recording (real time video recording).

[0238] TM_ZONE describes the time zone of the RTR disc. In the DVD_RTRspecifications, five different data fields (PL_CREATE_TM, VOB_REC_TM,FIRST_VOB_REC_TM, LAST_VOB_REC_TM, and VOBU_REC_TM) are specified. Thesefive different data fields are generally called REC_TM. REC_TM containsdata TZ_TY and TZ_OFFSET. TZ_TY describes a common universal time orlocal time, and TZ_OFFSET describes a date offset from the commonuniversal time in units of minutes.

[0239] STILL_TM describes the still time of a still picture in units ofseconds.

[0240] CHRS describes a character set code used in primary textinformation. With this CHRS, for example, an ISO8859-1 character setcode or shift JIS kanji code can be designated.

[0241] RSM_MRKI describes program chain number PGCN, program number PGN,cell number CN, marker point MRK_PT, and marker creation time MRK_TM.PGCN in this information indicates the number of the program chain wherea marker point is present. When the marker is present in an originalPGC, PGCN is set at “0”. PGN indicates the number of the program wherethe marker point is present. When a resume marker is present in a userdefined PGC, PGN is set at “0”. CN indicates a marker point in a targetcell. When the resume marker is present in a movie cell, MRK_PTdescribes a presentation time (PTM) using an RTR presentation timedescription format. MRK_TM describes the time of creation of the markerusing an RTR date description format.

[0242] REP_PICTI describes program chain number PGCN, program numberPGN, cell number CN, picture point PICT_PT, and representative picturecreation time CREAT_TM.

[0243] PGCN in this information indicates the number of the programchain where a representative picture of the disc is present. Therepresentative picture of the disc is designated by only the pointer inan original PGC. Hence, when this representative picture pointer ispresent, PGCN is set at “0”. PGN indicates the number of the programwhere the representative picture of the disc is present. When the resumemarker is present in a user defined PGC, PGN is set at “0”. CN indicatesthe number of the cell where the representative picture of the disc ispresent. PICT_PT indicates the representative image of the disc in thetarget cell. When the representative picture is present in a movie cell,PICT_PT describes the presentation time (PTM) using the RTR presentationtime description format. When this representative image is present in astill picture cell, PICT_PT describes a still picture VOB entry number(S_VOB_ENTN) in a corresponding still picture VOB group (S_VOG).CREAT_TM describes the time of creation of the representative picture ofthe disc using the RTR date description format.

[0244] M_AVFIT_SA describes the start address of movie AV fileinformation table M_AVFIT shown in FIG. 21 by a relative byte numberfrom the first byte of RTR_VMG.

[0245] S_AVFIT_SA describes the start address of still picture AV fileinformation table S_AVFIT shown in FIG. 21 by a relative byte numberfrom the first byte of RTR_VMG.

[0246] ORG_PGCI_SA describes the start address of original PGCinformation ORG_PGCI shown in FIG. 21 by a relative byte number from thefirst byte of RTR_VMG.

[0247] UD_PGCIT_SA describes the start address of user defined PGCinformation table UD_PGCIT shown in FIG. 21 by a relative byte numberfrom the first byte of RTR_VMG. If UD_PGCIT is not available,UD_PGCIT_SA is set at “0000 0000h”.

[0248] TXTDT_MG_SA describes the start address of text data managerTXTDT_MG shown in FIG. 21 by a relative byte number from the first byteof RTR_VMG. If TXTDT_MG is not available, TXTDT_MG_SA is set at “00000000h”.

[0249] MNFIT_SA describes the start address of manufacturer'sinformation table MNFIT shown in FIG. 21 by a relative byte number fromthe first byte of RTR_VMG. If MNFIT is not available, MNFIT_SA is set at“0000 0000h”.

[0250]FIG. 23 shows the data structure of the movie AF file informationtable (M_AVFIT) shown in FIG. 21.

[0251] M_AVFIT describes information of a movie AV file (fileRTR_MOV.VRO shown in FIG. 20), and contains movie AV file informationtable information M_AVFITI, one or more pieces of movie VOB streaminformation M_VOB_STI#1 to M_VOB_STI#n, and movie AV file informationM_AVFI.

[0252] M_AVFI is information of a movie AV file having a predeterminedfile name (RTR_MOV.VRO), and contains movie AV file information generalinformation M_AVFI_GI, one or more movie VOB information search pointersM_VOBI_SRP#1 to M_VOBI_SRP#n, and one or more pieces of movie VOBinformation M_VOBI#1 to M_VOBI#n.

[0253] One movie AV file can contain one or more VOBs, and each VOB hasmovie VOB information M_VOBI for VOB in M_AVFI. One or more pieces ofM_VOBI in M_AVFI are described in the same order as that of VOB datastored in the movie AV file.

[0254]FIG. 24 shows the data structure of the movie VOB information(M_VOBI) shown in FIG. 23. As shown in FIG. 24, M_VOBI contains movieVOB general information M_VOBI_GI, seamless information SMLI, audio gapinformation AGAPI, and time information TMAPI.

[0255] M_VOBI_GI shown in FIG. 24 contains VOB_TY which describes thetype of VOB, VOB_REC_TM which describes the recording time of the startfield in VOB using the RTR date description format, VOB_REC_TM_SUB whichdescribes the recording time (sub-second information) of the start fieldin VOB by the number of video fields, M_VOB_STIN which describes thenumber of movie VOB stream information, VOB_V_S_PTM which describes thepresentation start time of the first video field in VOB using the RTRpresentation time description format, and VOB_V_E_PTM which describesthe presentation end time of the last video field in the VOB using theRTR presentation time description format.

[0256] VOB_TY includes TE which indicates if that VOB has beentemporarily erased, A0_STATUS which indicates the status of audio stream#1, analog protection system APS which indicates the format of analogcopy protection or the ON/OFF state of this copy protection, SML_FLGwhich indicates if VOB is to be played back seamlessly, A0_GAP_LOC whichindicates if an audio gap is present in audio stream #0 and the locationof the audio gap if it is present, and A1_GAP_LOC which indicates if anaudio gap is present in audio stream #1 and the location of the audiogap if it is present.

[0257] VOB_REC_TM is updated to indicate the recording time of the startfield of the remaining VOB if the start field of a given VOB is deleted(erased).

[0258] More specifically, “new VOB_REC_TM=old VOB_REC_TM+playbackduration of erased field”.

[0259] On the other hand, if the playback duration of the erased fieldcannot be displayed in units of seconds (for example, when the playbackduration of the erased field is 60.5 sec),

[0260] We have “new VOB_REC_TM+new VOB_REC_TM_SUB=old VOB_REC_TM+oldVOB_REC_TM_SUB+playback duration of erased field”.

[0261] Since VOB_REC_TM describes the date of video recording, even whenaudio data has been modified, such modification has no influence onVOB_REC_TM.

[0262] The aforementioned RTR date description format will be brieflyexplained below. In this format, playback time PTM is expressed by a PTMbase and PTM extension. The PTM base is a value measured using 90 kHz asa unit, and the PTM extension is a value measured using 27 MHz as aunit.

[0263] SMLI shown in FIG. 24 contains VOB_FIRST_SCR which describes SCR(system clock reference) of the first pack of current VOB using the RTRpresentation time description format, and PREV_VOB_LAST_SCR whichdescribes SCR of the last pack in previous VOB using the RTRpresentation time description format.

[0264]FIG. 25 shows the data structure of the time map information(TMAPI) shown in FIG. 24.

[0265] Time map information TMAPI is used upon executing specialplayback (e.g., cell playback in the order unique to each user usinguser defined PGC) and time search.

[0266] Time map information TMAPI includes time map generationinformation TMAP_GI, one or more time entries TM_ENT#1 to TM_ENT#r, andone or more VOBU entries VOBU_ENT#1 to VOBU_ENT#q.

[0267] Each VOBU entry contains information of the size and playbacktime of VOBU. The VOBU size is presented in units of sectors (2 kbytes),and the playback time is presented in units of video fields (onefield={fraction (1/60)} sec in NTSC; one field={fraction (1/50)} sec inPAL).

[0268] Since the VOBU size is presented in units of sectors, asdescribed above, VOBU can be accessed using addresses in units ofsectors.

[0269] Each VOBU entry includes reference picture size information1STREF_SZ, VOBU playback time information VOBU_PB_TM, and VOBU sizeinformation VOBU_SZ.

[0270] Note that VOBU_PB_TM represents the playback time of VOBU ofinterest in units of video fields. On the other hand, reference picturesize information 1STREF_SZ represents the size of the first referencepicture (corresponding to I-picture in MPEG) of VOBU of interest inunits of sectors.

[0271] On the other hand, each time entry contains address information(VOBU_ADR) of the corresponding VOBU, and time difference information(TM_DIFF). This time difference information indicates the differencebetween the playback time designated by the time entry and the VOBUpresentation start time.

[0272] Assuming that the time interval (time unit TMU) between twosuccessive time entries is 10 sec, this time entry interval correspondsto 600 fields in, e.g., NTSC video.

[0273] Normally, the “time interval between neighboring VOBUS” isexpressed by the number of fields in the VOBU entry. As another method,“count value from a given VOBU to the next VOBU by a clock counter” maybe used to express the “time interval between neighboring VOBUs”.

[0274] For example, the “time interval between neighboring VOBUs” can beexpressed by the “difference value between the value of presentationtime stamp at the start position of one VOBU and the value of PTS at thestart position of the immediately succeeding VOBU”.

[0275] In other words, “the time interval in a specific unit can beexpressed by the difference value of the clock counter in that unit”.

[0276] Time map generation information TMAP_shown in FIG. 25 includesTM_ENT_Ns indicating the number of time entries in that time mapinformation, VOBU_ENT_Ns indicating the number of VOBU entries in thattime map information, time offset TM_OSF for that time map information,and address offset ADR_OFS of that time map information.

[0277] When a value (10 seconds or equivalent) corresponding to 600fields in NTSC video (or 500 fields in PAL video) is used as time unitTMU, time offset TM_OSF is used to represent the time offset within TMU.

[0278] When the VOBU size is expressed by the number of sectors, addressoffset ADR_OFS is used to indicate a file pointer from the beginning ofan AV file.

[0279] Time entry TM_ENT shown in FIG. 25 includes VOBU_ENTN indicatingthe number of the corresponding VOBU entry, TM_DIFF indicating the timedifference between the playback time of VOBU designated by the timeentry, and the calculated playback time, and VOBU_ADR indicating thetarget VOBU address.

[0280] When time unit TMU is expressed by 600 fields in NTSC (or whentime unit TMU is expressed by 500 fields in PAL), the “calculatedplayback time” with respect to time entry #j is given byTMU×(j−1)+TM_OSF.

[0281] On the other hand, VOBU_ADR indicates the target VOBU address bythe total size of VOBUs preceding VOBU of interest when the VOBU size isexpressed in units of sectors.

[0282] In the aforementioned data structure, in order to start playbackfrom the middle of certain VOBU, that access point must be determined.This access point is assumed to be a time entry point.

[0283] This time entry point is located at a position separated from theposition indicated by movie address information of VOBU by the timedifference indicated by time difference information TM_DIFF in timeentry TM_ENT. This time entry point serves as a special presentationstart point (or time search point) indicated by time map informationTMAPI.

[0284]FIG. 26 shows the data structure of the user defined PGCinformation table (UD_PGCIT) shown in FIG. 21.

[0285] When a trash PGC is created, the trash PGC is defined as a partof user-defined PGC information (UD_PGCI). If no trash PGC is defined, agiven PGCN may be assigned to a trash PGC.

[0286] UD_PGCIT includes user defined PGC information table informationUD_PGCITI, one or more user defined PGCI search pointers UD_PGCI_SRP#1to UD_PGCI_SRP#n, one or more pieces of user defined PGC informationUD_PGCI#1 to UD_PGCI#n.

[0287] All UD_PGCs are assigned program chain numbers PGCN ranging from1 to 99 in the description order of UD_PGCI_SRP in UD_PGCIT. This PGCNcan specify each PGC.

[0288] UD_PGCITI contains UD_PGCI_SRP_Ns indicating the number ofUD_PGCI_SRPs, and UD_PGCIT_EA indicating the end address of UD_PGCIT.

[0289] Note that the maximum value of UD_PGCI_SRP_Ns is set at, e.g.,“99”. UD_PGCIT_EA represents the end address of UD_PGCIT by a relativebyte number from the first byte of UD_PGCIT.

[0290] UD_PGCI_SRP includes start address UD_PGCI_SA of UD_PGCI. ThisUD_PGCI_SA represents the start address of UD_PGCI by a relative bytenumber from the first byte of UD_PGCIT.

[0291]FIG. 27 shows the data structure of the PGC information (PGCI).PGCI contains navigation information for program chain PGC.

[0292] Two different types of program chains, i.e., original PGC anduser defined PGC, are available (see the contents of RTR_VMG shown inFIG. 21). Original PGC has VOB and PGCI. However, user defined PGC doesnot have its own VOB, and refers to VOB in original PGC.

[0293] As shown in FIG. 27, PGC information (PGCI#i) includes PGCgeneral information PGC_GI, one or more pieces of program informationPGI#1 to PGI#m, one or more cell information search pointers CI_SRP#1 toCI_SRP#n, and one or more pieces of cell information CI#1 to CI#n.

[0294] Note that the start address of cell information CI can beindicated by CI_SA described as a relative byte number from the firstbyte of PGCI.

[0295] Here, PGCI of FIG. 27 corresponds to VTS_PGCI of FIG. 9, and thisVTS_PGCI corresponds to a combination of UD_PGCIF of FIG. 26 and anoriginal PGCI (ORG_PGCI).

[0296]FIG. 28 shows the contents of the PGC general information (PGC_GI)shown in FIG. 27.

[0297] This PGC_GI contains PG_Ns that describes the number of programsin PGC, and CI_SRP_Ns that describes the number of CI_SRPs in PGC.

[0298] In case of user defined PGC, PG_Ns is set at “0”. On the otherhand, the maximum number of programs PG in original PGC is “99”, and themaximum number of cells in PGC is “999”.

[0299] This PGC_GI can also include a trash PGC flag as in PGC_GI oftrash PGC shown in FIG. 15.

[0300]FIG. 29 shows the contents of the program information (PGI) shownin FIG. 27.

[0301] This PGI includes PG_TY which describes the type of program, C_Nswhich describes the number of cells in PG, primary text informationPRM_TXTI used in PG, search pointer number IT_TXT_SRPTN of IT_TXT wheretext data corresponds to PG, and thumbnail pointer information THM_PTRI.

[0302] Note that PRM_TXTI is constructed by a 128-byte field, and thefirst 64 bytes of that field are described by an ASCII character set.When an ASCII text is less than 64 bytes, “00” is written in blankbytes.

[0303] The second 64 bytes of the 128-byte field are used to describeprimary text of another character set (e.g., shift JIS or ISO8859-15).Note that the code of “another character set” is described in VMGI_MAT,and is shared by all the pieces of primary text information in the disc.

[0304] Note that a terminal control code that assumes a value rangingfrom “01h” to “1Fh” is never described in PRM_TXTI.

[0305] THM_PTRI describes information of a thumbnail pointer. That isTHM_PTRI includes CN that describes the number of the cell where thethumbnail pointer is present, and THM_PT that describes the thumbnailpointer in the target cell.

[0306] When the resume marker is present in a movie cell, THM_PTdescribes the presentation time (PTM) using the RTR presentation timedescription format.

[0307] On the other hand, when a thumbnail is present in a still picturecell, THM_PT describes a still picture VOB entry number (S_VOB_ENTN) ina corresponding still picture VOB group (S_VOG).

[0308] THM_PTRI may be optionally set or used in either an RTR recorderor player. When the RTR recorder does not have performance capable ofprocessing THM_PTRI, all the pieces of 8-byte THM_PTRI may be set at“FFh”. On the other hand, when the RTR player does not have performancecapable of processing THM_PTRI, it may simply ignore THM_PTRI.

[0309]FIG. 30 shows the data structure of the cell information (CI)shown in FIG. 27.

[0310] As shown in FIG. 30, there are two kinds of cell information,i.e., movie cell information M_CI and still picture cell informationS_CI.

[0311] Information (MC_C_EPI) that pertains to the entry point iswritten in movie cell information M_CI in navigation data file RTR.IFOshown in FIG. 20.

[0312]FIG. 31 shows the data structure of the movie cell information(M_CI) shown in FIG. 30.

[0313] As shown in FIG. 31, M_CI contains movie cell general informationM_C_GI, and one or more pieces of movie cell entry point informationM_C_EPI#1 to M_C_EPI#n.

[0314]FIG. 32 shows the contents of the movie cell general information(M_C_GI) shown in FIG. 31.

[0315] That is, M_C_GI contains C_TY which describes the type of cell,M_VOBI_SRPN which describes the number of the movie VOBI search pointercorresponding to VOB of this cell, C_EPI_Ns which describes the numberof pieces of cell entry point information, C_V_S_PTM which describes thepresentation start time of this cell using the RTR presentation timedescription format, and C_V_E_PTM which describes the presentation endtime of this cell using the RTR presentation time description format.

[0316] Note that C_V_S_PTM and C_V_E_PTM satisfy the followingconditions.

[0317] (1) In case of a cell in original PGC

[0318] C_V_S_PTM must be set in the first four VOBUs of thecorresponding VOB; and

[0319] C_V_S_PTM must be set in the last four VOBUs of the correspondingVOB.

[0320] (2) In case of a cell in user defined PGC

[0321] O_C_V_S_PTM≦C_V_S_PTM<C_V_E_PTM≦O_C_V_E_PTM must hold.

[0322] where O_C_V_S_PTM indicates the presentation start time of anoriginal cell corresponding to VOB referred to by this cell, andO_C_V_E_PTM indicates the presentation end time of an original cellcorresponding to VOB referred to by this cell.

[0323]FIG. 33 shows the contents of the movie cell entry pointinformation (M_C_EPI) shown in FIG. 31.

[0324] This M_C_EPI has two types (type 1 and type 2). M_C_EPI of type 1without any text information is composed of EP_TY and EP_PTM, andM_C_EPI of type 2 with text information is composed of EP_TY, EP_PTM,and PRM_TXTI. FIG. 33 shows M_C_EPI of type 2.

[0325] As shown in FIG. 33, M_C_EPI includes EP_TY that describes thetype of entry point, EP_PTM that describes the presentation time of theentry point using the RTR presentation time format, and PRM_TXTI thatdescribes primary text information and the like of the entry point.

[0326] Upon playback, the value EP_PTM and cell playback time areconverted into file pointers that point to VOBU by the time map TMAPinformation (see FIG. 25), and are also converted into physicaladdresses by the file system.

[0327] PRM_TXTI in M_C_EPI is constructed by a 128-byte field. The first64 bytes of that field are used to describe primary text using an ASCIIcharacter set. When ASCII text is less than 64 bytes, “00h” fills blankbytes. The latter 64 bytes of the 128-byte field are used to describeprimary text of another character set (e.g., shift JIS or ISO8859-15).Note that “another character set” is described in VMGI_MAT, and isshared by all the pieces of primary text information in the disc.

[0328] Note that a terminal control code that assumes a value rangingfrom “01h” to “1Fh” is never described in PRM_TXTI.

[0329] EP_TY in M_C_EPI is comprised of 1-byte data including a 2-bittype identification code. If this identification code is “00b ”, itindicates that M_C_EPI is of type 1 (empty primary text data or nodata); if the code is “01b ”, it indicates that M_C_EPI is of type 2(primary text data).

[0330] This EP_TY has a 6-bit reserved field in addition to the 2-bittype identification code that identifies type 1 or 2. Using some or allthe bits of this reserved field, the contents of PRM_TXTI in M_C_EPI canbe further specified. (If all the six bits are used, a maximum of 64different specifications may be made. More than 6 bits may be assignedto this designation code to specify more types.)

[0331] The bits using this reserved field will be referred to as adesignation code for designating the contents of the primary textinformation hereinafter.

[0332] Specific bits in the designation code can designate whetherPRM_TXTI in M_C_EPI shown in FIG. 33 is “text information” with“information type” and/or “information date” or “text information”without “information type” and/or “information date”.

[0333] Furthermore, specific bits in the designation code can designatewhether PRM_TXTI in M_C_EPI shown in FIG. 33 is “text information” withcorresponding “thumbnail information” in addition to “information type”and/or “information date”, or “text information”, without “thumbnailinformation”. (The “thumbnail information” corresponds to, e.g.,thumbnail pointer information THM_PTRI shown in FIG. 29.)

[0334] Moreover, specific bits in the designation code can designatewhether PRM_TXTI in M_C_EPI shown in FIG. 33 consists of “thumbnailinformation” alone without any “text information” or “thumbnailinformation” with “text information”.

[0335] When the designation code (not shown) in EP_TY designates“information type”, “information date”, and text information” shown inFIG. 33, these pieces of information can be used to express thefollowing contents.

[0336] More specifically, “information type” describes an attribute ofthe entry point, “information date” describes the date of registration(recorded on the disc) of the entry point, and “text information”describes additional information (a brief comment of a picture at theentry point) that pertains to the entry point.

[0337] The attributes of the entry point described in “information type”include:

[0338] information type [1]=0, user mark (the user registers the entrypoint)

[0339] information type [1]=1; set mark (an apparatus such as a DVD_RTRvideo recorder or the like registers the entry point)

[0340] information type [1]=3; erasion prohibition mark (correspondingto the erasion level flag described in the cell type in C_PBI shown inFIG. 12)

[0341] information type [1]=4; trash box mark (corresponding toinformation of trash PGC shown in FIG. 16)

[0342] information type [1]=5 to 7; other marks Note that [1] ininformation type [1] means the first data field of the information type.If this data field has a 3-bit configuration, information type [1] canexpress eight different marks.

[0343]FIG. 34 shows an example of the arrangement of an apparatus (RTRvideo recorder) for recording (recording/playing back) digital movingpicture information (video program or the like) at variable recordingrate using optical disc (DVD-RAM, DVD-RW, or DVD-R disc) 10 shown inFIG. 1.

[0344] The apparatus main body of the RTR video recorder shown in FIG.34 has disc drive 32 for rotating a recording disc and reading/writinginformation on the disc, encoder 50 which constructs the recording side,decoder 60 which constructs the playback side, and microcomputer (MPU)30 for controlling operations of the overall apparatus.

[0345] Encoder 50 comprises analog-to-digital converter (ADC) 51,selector 52, video encoder 53, audio encoder 54, sub-picture encoder 55,formatter 56, and buffer memory 57.

[0346] ADC 51 receives an external analog video signal+external analogaudio signal from AV input 42, or analog TV signal+analog audio signalfrom TV tuner 44. This ADC 51 converts the input analog video signalinto digital data at, e.g., a sampling frequency=13.5 MHz and the numberof quantization bits=8. (More specifically, luminance component Y, colordifference component Cr (or Y-R), and color difference component Cb (orY-B) are respectively quantized by 8 bits.)

[0347] Likewise, ADC 51 converts the input analog audio signal intodigital data at, e.g., a sampling frequency=48 kHz and the number ofquantization bits=16.

[0348] When an analog video signal and digital audio signal are input toADC 51, the digital audio signal passes through ADC 51.

[0349] When a digital video signal and digital audio signal are input toADC 51, these signals pass through ADC 51.

[0350] A digital video signal output from ADC 51 is supplied toformatter 56 via selector 52 and video encoder 53. Also, a digital audiosignal output from ADC 51 is supplied to formatter 56 via audio encoder54.

[0351] Selector 52 selects a signal output from video mixer 200 andsends it to video encoder 53 when a reduced-scale image (thumbnailpicture) for editing (to be described later) is to be recorded.

[0352] Video encoder 53 has a function of converting the input digitalvideo signal into a digital signal compressed at variable bit rate onthe basis of the MPEG2 or MPEG1 specifications.

[0353] Audio encoder 54 has a function of converting the input digitalaudio signal into a digital signal (or linear PCM digital signal)compressed at fixed bit rate on the basis of the MPEG or AC-3specifications.

[0354] When a digital video signal (for example, a signal from a DVDvideo player with an independent output terminal of a sub-picturesignal) with the structure shown in FIGS. 2 to 5 or FIGS. 17 and 18 isinput from AV input 42, or when a DVD video signal with such datastructure is broadcasted and is received by TV tuner 44, a teletextsignal (closed caption) component in the DVD video signal is input tosub-picture encoder 55. Sub-picture data input to sub-picture encoder 55is arranged into a predetermined signal format, and is then sent toformatter 56.

[0355] Formatter 56 executes predetermined signal processing of theinput video signal, audio signal, sub-picture signal, and the like usingbuffer memory 57 as a work area, and outputs recording data that matchesthe aforementioned format (file structure) to data processor 36.

[0356] In this processing, a cell is set as a minimum unit of mainpicture data (video data), and cell playback information C_PBI shown inFIG. 11 (or cell information CI shown in FIG. 27) is created. Then, theconfiguration of cells that construct program chain PGC, attributes ofmain picture, sub-picture, and audio data, and the like are set (some ofthese pieces of attribute information use information obtained uponencoding the respective data), and information management tableinformation (VMGI, VTSI shown in FIG. 3; or RTR_VMG shown in FIG. 20)including various kinds of information is created.

[0357] Encoded main picture data, audio data, and sub-picture data aresegmented into packs each having a predetermined size (2,048 bytes).Dummy packs are inserted into these packs, as needed. Note that timestamps such as PTS (presentation time stamp), DTS (decode time stamp),and the like are described in packs other than dummy packs, as needed.As for PTS of sub-picture data, a time arbitrarily delayed from PTS ofmain picture data or audio data in the identical playback time band canbe described.

[0358] Data cells are arranged in units of VOBUs to allow playback inthe time code order of data, thus forming VOB consisting of a pluralityof cells. VOBS that combines one or more VOBs is formatted into a filestructure that matches VTS shown in FIG. 3 or RTR_MOV.VRO shown in FIG.20.

[0359] The RTR video recorder shown in FIG. 34 comprises disc drive 32,temporary buffer memory 34, data processor (D-PRO unit) 36, and systemtime clock (STC) 38 as means for reading/writing (recording and/orplaying back) information with respect a recordable DVD_RTR disc.

[0360] Temporary buffer memory 34 is used to buffer a given amount ofdata to be written on the disc (data output from encoder 50) via D-PROunit 36, and to buffer a given amount of data played back from the disc(data input to decoder 60) via D-PRO unit 36.

[0361] For example, when temporary buffer memory 34 comprises a 4-Mbytesemiconductor memory (DRAM), it can buffer recording or playback datafor approximately 8 seconds at an average recording rate of 4 Mbps. Whentemporary buffer memory 34 comprises a 16-Mbyte EEPROM (flash memory),it can buffer recording or playback data for approximately 30 seconds atan average recording rate of 4 Mbps. Furthermore, when temporary buffermemory 34 comprises a 100-Mbyte, very small HDD (hard disc drive), itcan buffer recording or playback data for 3 minutes or more at anaverage recording rate of 4 Mbps. Also, temporary buffer memory 34 canalso be used to temporarily store recording information when the disc isused up during recording, until that disc is exchanged by a new disc.

[0362] D-PRO unit 36 supplies DVD recording data from encoder 50 to discdrive 32, receives a DVD playback signal played back from the disc fromdrive 32, rewrites management information (directory record, VMGI_MAT,VTSI_MAT, RTR_VMG, and the like) recorded on the disc, and erases data(some or all fields of VTS, RTR_MOV.VRO, or the like) recorded on thedisc, under the control of MPU 30.

[0363] MPU 30 includes a ROM written with various control programs andthe like, a RAM which provides a word area required for executingprograms, and the like, in addition to a CPU core of the microcomputer.

[0364] This MPU 30 executes processes such as free space detection ofthe disc which is being used in recording, recording space (the numberof recorded packs) detection, remaining space detection, warning,recording mode change instruction, and the like, in accordance with thecontrol programs stored in its ROM.

[0365] Furthermore, MPU 30 has a function of designating an erasionlevel appending range to cell units (or entry point units), a functionof setting an erasion level, a function of dividing a cell, a functionof detecting the erasion level, and the like. With these functions, useroperability of the RTR video recorder system can be improved.

[0366] Of the execution results of various control programs by MPU 30,the contents the user of the DVD_RTR video recorder should know aredisplayed on display panel 48 of the DVD_RTR video recorder, or aredisplayed on a monitor display as on-screen display (OSD).

[0367] Decoder 60 comprises separator 62 for separating the respectivepacks from DVD_RTR playback data with the aforementioned pack structure,memory 63 used upon executing pack separation and other signalprocesses, video decoder 64 for decoding contents of video packsseparated by separator 62, sub-picture decoder 65 for decoding thecontents of sub-picture packs separated by separator 62, audio decoder68 for decoding the contents of audio packs separated by separator 62,and video processor 66 for appropriately mixing sub-picture data fromsub-picture decoder 65 with video data output from video decoder 64,i.e., superposing sub-picture data such as menus, highlight buttons,superimposed dialogs, and the like on main picture data, and outputtingthem.

[0368] Note that video decoder 64 incorporates a thumbnail picturegenerator for generating an image (thumbnail picture) obtained byextracting and reducing a predetermined I-picture portion from, e.g.,MPEG video data in accordance with a command from MPU 30.

[0369] This thumbnail picture is output to an external TV monitor viavideo mixer 200 and DAC (digital-to-analog converter) 67, or is suppliedto video encoder 63 via video mixer 200 and selector 52.

[0370] The thumbnail picture data supplied to video encoder 53 can bewritten in a predetermined dummy pack (see FIGS. 18 and 19) by formatter56.

[0371] The output from video processor 66 is supplied to video mixer200. Frame memory 201 used for mixing video data is connected to videomixer 200.

[0372] A digital signal output from video processor 66 via video mixer200 is supplied to an external monitor (not shown) such as a televisionreceiver via video DAC 67.

[0373] Or the digital signal from video processor 66 may be supplied toa built-in liquid crystal display (not shown) or the like of theapparatus.

[0374] The output from audio decoder 68 is supplied to an externaldevice via audio DAC 69.

[0375] The digital video output from video mixer 200 or digital audiooutput from audio DAC 68 may be externally output via an appropriatedigital output interface, although pertinent connections are not shownin the drawings.

[0376] Furthermore, key input unit 49, and display panel 48 fordisplaying the operation state and the like of the DVD-RTR recorder areconnected to MPU 30.

[0377]FIG. 35 is a flow chart for explaining image recording by theapparatus shown in FIG. 34.

[0378] Upon receiving an image recording command from key input unit 49(or a preserved recording program or key operation at a remotecontroller (not shown)), MPU 30 shown in FIG. 34 reads management datafrom disc 10 via disc drive 32 (step A2), and determines a write area(step A4).

[0379] MPU 30 then sets management data (creates VMGI and VTSI filesshown in FIG. 3; or creates RTR_VMG file shown in FIG. 20) in amanagement area to be able to write data in the determined area, andsets the write start address of video data in disc drive 32 to preparefor data recording (step A5).

[0380] If there is no recordable space (NO in step A3), a warning toneor message is generated or displayed.

[0381] MPU 30 then resets the time in STC 38. Note that STC 38 is asystem timer, and recording or playback is done with reference to themeasurement value of this STC.

[0382] Furthermore, MPU 30 makes other setups (steps A6 and A7).

[0383] The flow of a video signal upon recording is as follows.

[0384] AV signals input from TV tuner 44 shown in FIG. 34 or an externaldevice are A/D-converted, a video signal is supplied to video encoder53, and an audio signal is supplied to audio encoder 54. Also, ateletext signal or the like is supplied from TV tuner 44 to SP encoder55.

[0385] The respective encoders (53 to 55 in FIG. 34) compress andpacketize the input signals (note that each packet is formed to have asize of 2,048 bytes per pack), and input the packets to formatter 56.The respective encoders determine PTS and DTS of each packet inaccordance with the value of STC 38, as needed.

[0386] Formatter 56 temporarily stores packet data in buffer memory 57,then packs the input packet data, and mixes them in units of GOPs.Formatter 56 appends a navigation pack to the head of each GOP, asneeded, and inputs packs to D-PRO unit 36.

[0387] D-PRO unit 36 forms ECC groups in units of 16 packs, appends ECCdata to these groups, and sends them to disc drive 32. When disc drive32 is not ready to record on the disc, D-PRO unit 36 temporarilytransfers ECC group data to temporary buffer memory 34, and waits untildisc drive 32 is ready to record. When disc drive 32 is ready to record,recording is started. In this case, a large-size memory is assumed astemporary buffer memory 34 so as to store recording data for severalminutes or more by high-speed access.

[0388] At the end of recording, MPU 30 records address data ofnavigation packs (or navigation data) in fast-forwarding or rewindingdata fields of the respective navigation packs (or navigation data), andrecords required information on the management area after recording,thus ending recording (steps A8 to A14).

[0389] Note that MPU 30 shown in FIG. 34 can read out various kinds ofinformation from the file management area and the like on disc 10 shownin FIG. 1, and can write various kinds of information on the recordingarea of this disc by sending commands to D-PRO unit 36 via a data bus.

[0390] At the end of recording, erasion level flags set in units ofcells, which are used by the RTR video recorder system are cleared topermit playback (step A13). That is, playback of all cells is permittedupon initial recording.

[0391] This erasion level flag is described in C_PBI (FIG. 12). When anarchive flag (erasion prohibition flag) is stored in VMG, it is alsocleared.

[0392] If M_C_EPI (FIG. 33) in RTR_VMG includes the erasion level flagor trash PGC information, it is also cleared.

[0393] The data processing upon playback is as follows.

[0394] Upon receiving a playback command, MPU 30 reads data on themanagement area via disc drive 32 and D-PRO unit 36, and determines theplayback address. MPU 30 then sends the determined playback data addressand a read command to disc drive 32.

[0395] In response to the received command, disc drive 32 reads outsector data from the disc, performs error correction using D-PRO unit36, and outputs the readout data to decoder 60 in the form of pack data.

[0396] In decoder 60, separator 62 receives and packetizes the readoutpack data. Depending on data contents, MPU 30 transfers video packetdata (MPEG video data) to video decoder 64, audio packet data to audiodecoder 68, and sub-picture packet data to SP decoder 65, and saves thecontents of navigation packs (or navigation data) in its internal memoryto use them when required. In this manner, MPU 30 can quickly accessnavigation data anytime.

[0397] At the beginning of transfer of the respective packet data, PTSincluded in a header is loaded to STC 38 (MPU 30 sets PTS in anavigation pack in STC, or video decoder 64 automatically sets PTS ofvideo data in STC 38). After that, the respective decoders play backdata in synchronism with-PTS values in packet data, and moving picturedata with audio and superimposed dialog data can be played back on a TVmonitor.

[0398] In some cases, an erasion level flag is described in cellplayback information (CPB_I), as shown in FIG. 12. Hence, before cellplayback, the erasion level is checked, and if the cell is temporarilyerased (i.e., level=01h), the control skips playback of that cell andstarts processes of the next cell.

[0399] When a temporary erase flag is described in VOB information(VOB_GI), the VOB information of VOB entered in cell information is readout before reproducing (playback) the cell. Then, the status of thetemorary erase flag is checked. If the status indicates atemporarily-eased state (or the flag=01h), the playback of that cell isskipped, and the process of playing back the subsequent cell isactivated.

[0400] That is, in this system, since erasion level flags are set inunits of cells, erasion setting (to automatically exclude a given cellfrom those to be played back) can be done in units of cells, thusallowing more flexible presentation and management.

[0401] Accordingly, a temporary erasion process is done as follows.

[0402]FIGS. 36 and 37 are flow charts for explaining erasion levelsetting (temporary erasion process). FIG. 38 shows examples of windowsdisplayed in this temporary erasion process, and FIG. 39 is a view forexplaining the principle of cell division upon executing the temporaryerasion process.

[0403] When an erasion key of key input unit 49 shown in FIG. 34 (or aremote controller (not shown)) has been pressed, MPU 30 shown in FIG. 34starts the process shown in FIGS. 36 and 37.

[0404] 1) It is checked if there is PGC with the trash PGC flag=01h inPGC_GI shown in FIG. 15, i.e., trash PGC (step B2). If no trash PGC isfound, a file of trash PGC is prepared (step B3).

[0405] 2) The user selects a title (VTS or PGC) (step B4).

[0406] 3) A time bar corresponding to the playback time of the selectedtitle (VTS or PGC), and a cursor for designating that time range (seethe time bar in 15-min increments shown in FIG. 38) are displayed (stepB5).

[0407] In this time bar display, PGC of interest may be divided in unitsof cells using the dotted lines and the like, so as to inform the userthat the range bounded by the dotted lines corresponds to an identicalscene (one PGC). For example, in image sensing using a video camera, therange from the beginning of recording to a pause or the end of recordingcorresponds to this scene. In a TV drama, the range from a given CM tothe next CM corresponds to this scene.

[0408] 4) The user designates the erasion start position using a cursorkey and marker key of key input unit 49 (step B6), and the VOBU addresscorresponding to the designated position, and the like are saved in theinternal work memory (not shown) of MPU 30 (step B7).

[0409] At this time, when the start I-picture of VOBU pointed by thecursor is simultaneously displayed on the cursor window as areduced-scale image (thumbnail picture), the user can recognize thecontents of a cell at the cursor position, thus allowing easy operation.

[0410] The playback time at the cursor position at that time can also bedisplayed. The playback time can be calculated by C_PBTM+C_ELTM withinthe range from the first cell to the immediately preceding cell of thetitle with reference to cell elapse time C_ELTM (FIG. 7) in a navigationpack and cell playback time C_PBTM (FIG. 12) in cell playbackinformation.

[0411] Or the playback time at the cursor position can be calculatedwith reference to the contents of time map information TMAPI (FIG. 25)and movie cell general information M_C_GI (FIG. 32).

[0412] 5) The user designates the erasion end position using the cursorkey and marker key of key input unit 49 (step B8), and the VOBU addresscorresponding to the designated position and the like are saved in thework memory (step B9).

[0413] 6) Looking at the display in FIG. 38, the user confirms if he orshe agrees with the current selected range (the displayed range fromerasion start to erasion end) (step B10). If the user disagrees withthat range (NG in step B10), the work memory is cleared to repeat theprocesses in steps B6 to B9.

[0414] 7) If the user agrees with the displayed selected range (OK instep B10), it is checked if cell division is necessary at the set startposition, i.e., if the cell start position matches the set startposition (step B11).

[0415] If no cell division is necessary at the start position (NO instep B11), the flow advances to step B16 in FIG. 37.

[0416] 8) If cell division is necessary at the start position (YES instep B11), the cell to be divided (CELL_N) is determined based on startand end VOBUs in C_PBI of each cell (step B12). Alternatively, the cellnumber which was determined and saved upon setting by the cursor is usedas CELL_N. Cell division is done using this CELL_N.

[0417] More specifically, start address C_LVOBU_SA, end addressC_LVOBU_EA, and cell playback time C_PBTM of last VOBU in C_PBI ofCELL_N are saved in the work memory, and C_LVOBU_SA, C_LVOBU_EA, andC_PBTM are rewritten on the basis of search information of a navigationpack of VOBU to be divided (step B13).

[0418] Then, C_PBI next to CELL_N is moved by one cell (step B14).

[0419] Note that the processes in step B13 and B14 can also be doneusing time map information TMAPI shown in FIG. 25 and PGC informationPGCI shown in FIG. 27.

[0420] At the place reached in step B14, new cell playback informationC_PBI with the following contents is recorded (step B15 in FIG. 37).

[0421] That is, the same cell category C_CAT as that of CELL_N, playbacktime C_PBTM of the divided cell, start address C_FVOBU_SA of first VOBUin the divided cell, end address C_FILVU_EA of first ILVU in the dividedcell, start address C_LVOBU_SA of last VOBU in the divided cell, and endaddress C_LVOBU_EA of last VOBU in the divided cell are recorded as newcell playback information C_PBI of the divided cell.

[0422] 9) Subsequently, the erasion level flag of the setting start cell(e.g., cell 3 in the lower cell array in FIG. 39) is set in a playbackprohibition (temporary erasion) state.

[0423] The same processes as those in steps B11 to B15 are repeated fora cell at the setting end position (steps B16 to B20).

[0424] 10) That is, it is checked if cell division is necessary at thesetting end position (i.e., to check if the cell end position matchesthe setting end position). If no division is necessary.(NO in step B16),the flow advances to step B21.

[0425] 11) If the end cell must be divided (YES in step B16), the cellto be divided (CELL_M) is determined (that cell is determined based onstart and end VOBUs in C_PBI of each cell. Or the cell number which wasdetermined and saved upon setting by the cursor is used). The determinedcell is divided (step B17).

[0426] More specifically, C_FVOBU_SA to C_LVOBU_EA, and C_PBTM in cellplayback information C_PBI of CELL_M are saved, and the saved C_FVOBU_SAto C_LVOBU_EA, and C_PBTM are rewritten based on search information ofVOBU to be divided (step B18).

[0427] Then, C_PBI next to CELL_M is moved by one cell (step B19).

[0428] At the place reached in step B19, new cell playback informationwith the following contents is recorded (step B20).

[0429] That is, the same cell category C_CAT as that of CELL_M, playbacktime C_PBTM of the divided cell, start address C_FVOBU_SA of first VOBUin the divided cell, end address C_FILVU_EA of first ILVU in the dividedcell, start address C_LVOBU_SA of last VOBU in the divided cell, and endaddress C_LVOBU_EA of last VOBU in the divided cell are recorded as newcell playback information C_PBI of the divided cell.

[0430] 12) The erasion level flag of each cell before the setting endcell (e.g., cell 4 in the lower cell array in FIG. 39) is set in aplayback prohibition (temporary erasion) state (step B21).

[0431] 13) C_PBI of each temporary erased cell (e.g., cells 3 and 4 inthe lower cell array in FIG. 39) is added to trash PGC, and original PGCnumber PGC_N and original cell number C_ID_N are recorded in this C_PBI(FIG. 16) (step B22).

[0432] 14) If cells to be subjected to erasion level setting (temporaryerasion process) still remain (NO in step B23), operation repeats itselffrom step B6 in FIG. 36.

[0433] Upon completion of erasion level setting (temporary erasionprocess) (YES in step B23), pertinent data are written in trash PGCgeneral information (FIG. 15) to record data required for filemanagement (step B24).

[0434] Note that the processes for dividing a cell in steps B11 to B24can also be done using information shown in FIGS. 21 to 33. Morespecifically, movie cell M_C_GI (FIG. 32) and movie cell entry pointinformation M_C_EPI (FIG. 33) of M_CI of the divided cell can berewritten on the basis of time map information TMAPI (FIG. 25) thatcorresponds to cell division.

[0435] In this case, data in a navigation pack is not necessary, and thecell division position can be specified by entry point informationM_C_EPI#1 to M_C_EPI#n shown in FIG. 31. Also, erasion level (temporaryerasion) setting information can be described in character informationin M_C_EPI shown in FIG. 33.

[0436]FIG. 40 is a flow chart for explaining recovery (restoration) andactual erasion of a cell in which an erasion level flag is set in atemporary erasion state. FIG. 41 shows examples of windows displayedupon recovering (restoring) and actually erasing a cell in which anerasion level flag is set.

[0437] In this embodiment, a process for recovering from a temporaryerasion state (playback prohibition state) to a playback permitted stateis done in units of cells. (Although not shown as a flow chart, asimilar recovery process can be done in units of entry points.)

[0438] 1) The user clicks a trash box mark (icon) by key operation onthe remote controller (not shown) (or by mouse operation (not shown))while observing the upper left window in FIG. 41 (step C2).

[0439] 2) If trash PGC has been selected upon clicking the trash icon,MPU 30 shown in FIG. 34 reads information (FIGS. 15 and 16) of trash PGCfrom disc 10 (step C3).

[0440] 3) Then, a time bar is displayed in accordance with the playbacktime of trash PGC, as illustrated on the upper central window in FIG. 41(step C4). At this time, title text “contents of trash box” is alsodisplayed to indicate trash PGC. Furthermore, a cursor for designating acell to be recovered to a playback permitted state, and a reduced-scaleimage (thumbnail picture) of I-picture of that cell are displayed (stepC5).

[0441] 4) The user then designates a cell to be recovered to theplayback permitted state (i.e., to cancel the temporary erasion state)using a cursor key and marker key (not shown) on the remote controller(step C6).

[0442] If the aforementioned erasion cancel designation is erroneouslydone or cells to be erasion-canceled still remain (NG in step C7),processes in steps C4 to C6 are repeated.

[0443] 5) After the designated cell is confirmed (OK in step C7), theuser determines if the designated cell is to be recovered to theplayback permitted state or to be actually erased (step C8).

[0444] 6) When the designated cell (or VOB) is to be recovered to theplayback permitted state, MPU 30 specifies an original cell (or VOB) ofthe selected cell (or VOB) by referring to PGC_N and C_ID_N (or CI) oftrash PGC shown in FIG. 16. MPU 30 then clears the erasion level flag(FIG. 12) of that original cell (or VOB) to 00h (playback permitted),and deletes information (PGC_N and C_ID_N; or CI) of the cell (or VOB)in the temporary erasion state from trash PGC (step C9).

[0445] 7) As to cell, when the designated cell is to be actually erased,MPU 30 specifies an original cell of the selected cell by referring toPGC_N and C_ID_N of trash PGC shown in FIG. 16. MPU 30 erases thatoriginal cell, and deletes information (PGC_N and C_ID_N in FIG. 16) ofthe erased cell from trash PGC (step C10).

[0446] 7*) As to VOB, when the designated VOB is to be actually erased,MPU 30 erases the target cell information CI and shifts upward thesubsequent CI to remove the space of erased CI where PGC_GI and PGI areupdated (step C10).

[0447] At this time, the start and end file pointers (FPs) at the VROfile are detected according to the VOB information (VOBI) (step C10).

[0448] The target VOBI is then erased, and the space of the erased VOBIis removed where the movie AV file general information (M_AVFI_GI) andmovie VOBI search pointer (M_VOBI_SRP) are updated (step C10).

[0449] Thereafter, the target video data is erased from the VRO file, tothereby release from the file system the data between the start and endfile pointers (step C10).

[0450]FIG. 42 is a flow chart showing automatic erasion (disc arrangingprocess) of a cell in which an erasion level flag is set. FIG. 43 showsexamples of windows displayed upon erasing a cell in which an erasionlevel flag is set.

[0451] The disc arranging process shown in FIG. 42 is executed when thetimer reservation time before the beginning of recording is longer thanthe time corresponding to the remaining space of disc 10, when theremaining space of disc 10 becomes short during recording, or when theuser actually wants to erase a cell in a temporary erasion state intrash PGC.

[0452] More specifically, when the remaining space of disc 10 becomesshort or when the user inputs an erasion command, MPU 30 executes thedisc arranging process shown in FIG. 42.

[0453] 1) If the control enters this process, message “disc arrangingwill be done” is displayed on the TV monitor screen, as illustrated onthe upper left window in FIG. 43 (step D2).

[0454] 2) MPU 30 then instructs disc drive 32 to start disc arranging(step D3).

[0455] In response to this instruction, the internal MPU (not shown) ofdisc drive 32 executes the following process of the disc arranging mode(step D10).

[0456] More specifically, the internal MPU checks based on the contentsof the trash PGC flag shown in FIG. 15 if trash PGC is present oncurrently set disc 10 (step D11).

[0457] If trash PGC with a trash PGC flag=01h is found, the internal MPUreads out information (FIGS. 15 and 16) of that PGC from disc 10 (or abuffer memory if it is recorded on the buffer memory of temporary buffermemory 34) (step D12).

[0458] The internal MPU erases all original cells in a temporary erasionstate (i.e., those with an erasion level flag (FIG. 12)=01h) in trashPGC on the basis of the readout information (PGC_N and C_ID_N in FIG.16), and also erases empty trash PGC (step D13).

[0459] The internal MPU then sends back to MPU 30 status indicating thaterased cells exist (steps D14 and D15).

[0460] On the other hand, if no trash PGC is found on that disc (NO instep D11), the internal MPU sends back to MPU 30 status indicating thata cell to be erased does not exist (steps D17 and D15).

[0461] 3) While disc drive 32 is executing the processes in steps D11 toD17, message “disc arranging is now performed” illustrated on the upperright window in FIG. 43 is displayed on the TV monitor screen (step D4).

[0462] 4) If disc drive 32 has completed the processes in steps D11 toD17 and sends back status (YES in step D5), MPU 30 checks if erasedcells exist.

[0463] 5) If erased cells exist (YES in step D6), since the remainingspace of disc 10 increases accordingly, the remaining recordable time isrecalculated (step D7).

[0464] This recalculation can be made on the basis of the number ofsectors of the unrecorded space of disc 10, the mode (MPEG1 or MPEG2)used in the subsequent recording, the average recording rate (bits/sec)used in the subsequent recording, contents (%) of dummy packs, and thelike.

[0465] If no erased cell exists (NO in step D6), since the remainingspace of disc 10 remains the same even after disc arranging, the flowskips the recalculation of the remaining recordable time.

[0466] 6) After the remaining time of disc 10 is obtained, as describedabove, message “disc arranging completed successfully. Remainingrecordable time will be 6 min 15 sec with average rate of 4 Mbps”, asshown at the center in FIG. 43, is displayed on the TV monitor screen(step D8).

[0467] With this process, the recorded files on the disc in use arearranged, and temporary erased cells are actually erased, thusincreasing the recordable space of the arranged disc.

[0468] Also, the erasion level can be set in small units.

[0469]FIG. 44 is a flow chart for explaining playback upon playing backthe contents on the disc that describes the aforementioned erasion levelinformation.

[0470] Upon receiving a playback start command, it is checked if thedisc is a DVD_RTR disc (step E2).

[0471] If the disc is a DVD_RTR disc, management information VMGI isread (step E3), and menus and the like are displayed, as needed.

[0472] If a title set to be reproduced or played back (or a title to beplayed back) has been selected (step E4), VTSI (or RTR_VMG) of thattitle is read (step E5) to set up an environment, and PGC information(PGCI) or VOB information (VOBI) is stored.

[0473] The title (or program) is selected and determined (step E6), anda program number, cell number, and the like to be played back aredetermined to determine the playback order and the like (step E7).

[0474] The video decoder, sub-picture decoder, audio decoder, and thelike are initially set up (step E8).

[0475] Subsequently, a preprocess command is executed (step E9), and itis checked if the read cell is a temporary erased cell (step E10).

[0476] Incidentally, no preprocess command is executed in a RTR_DVDsystem.

[0477] If the read cell has no flag of the erasion state (i.e., it isnot in the temporary erasion state), cell playback is executed (stepE11).

[0478] If the read cell describes a flag of the erasion state (temporaryerasion state), playback of that cell is skipped, and the next cell isplayed back.

[0479] After the last cell has been played back (YES in step E12), astill picture is played back for a preset period of time (apredetermined period of time including zero time) (step E13), and apostprocess command is executed (step E14).

[0480] If the last cell has not been played back yet (NO in step E12),the cell number is incremented by one (step E18), and the processes insteps E10, E11, and E18 are repeated until the last cell is played back.

[0481] Upon completion of playback of the last cell and execution of thepostprocess command, if the user has pressed a stop button on the remotecontroller to quit playback (YES in step E15), a process for completingplayback is executed (step E16), and the apparatus (RTR video recorder)is at rest to wait for the next user command.

[0482] On the other hand, even after completion of playback of the lastcell and execution of the postprocess command, if the user has pressed aplay button on the remote controller to direct playback start (NO instep E15), the processes in steps E9 to E15 are executed again.

[0483] Incidentally, no postprocess command is executed in the RTR_DVDsystem.

[0484]FIGS. 45-48 are a set of flow charts explaining a manner ofdividing video objects (VOB) and cells.

[0485]FIG. 49 explains a manner of dividing cells where one cell isequal to one VOB, and FIG. 50 explains a manner of dividing VOBs whereone cell is not equal to one VOB.

[0486] As shown in FIG. 45, when a user depresses a key for setting theerase prohibition, a control device (e.g., MPU 30 in FIG. 34) acts ondecoder 60, etc., so that the time bar and thumbnail picture(s) as shownin FIG. 38 are displayed on the screen of a TV monitor (not shown) (stepST100).

[0487] The user may move the cursor displayed on the screen, usingcursor keys of key input section 49 or a remote controller (not shown).When the cursor is moved, the content of displayed thumbnail picture ischanged correspondingly. During the cursor key manipulation, the usercan select a picture in the PGC (step ST102). At this time, the selectedpicture indicates the start portion of the erase prohibition.

[0488] Then, the displayed position of the selected picture movesdownward, and the running time of leading VOBU (video object unit) ofthe moved picture is displayed on the screen. At this time, the startPTM (presentation time) of this VOBU is stored in a RAM or register (notshown) of MPU 30 (step ST104).

[0489] The user may further select a picture in the PGC (step ST106).

[0490] Then, the displayed position of the selected picture movesdownward, and the end PTM of selected VOBU is stored in the RAM orregister (not shown) of MPU 30 (step ST108).

[0491] At this time, the user can confirm his/her selections of thedisplayed pictures (step ST110).

[0492] If the user is not satisfied (NG at step ST110), the processreturns to step ST100.

[0493] When the user is satisfied (OK at step ST110), it is checkedwhether a division of the start VOB is necessary (step ST112).

[0494] If the division of the start VOB is not necessary (NO at stepST112), the process goes to step ST122 described hereinafter.

[0495] When the division of the start VOB is necessary (YES at stepST112), the VOB (VOB#n) to be divided (which is located at the startportion) is determined (step ST114).

[0496] Then, start PTM of VOB#n (VOB_S_PTM), end PTM of VOB#n(VOB_E_PTM), and time map information (TMAPI) are stored in the RAM orregister of MPU 30 (step ST116).

[0497] At this time, the end PTM of VOBU#m-1 which proceeds by one tothe VOBU of the start PTM of the determined area is set at VOB_E_PTM(step ST116).

[0498] Further, a time entry (TM_ENT) and a VOBU entry (VOBU_ENT) ofVOBU next to VOBU#m-1 are deleted, and the number of each of TM_ENT andVOBU_ENT of time map general information (TMAP_GI) are updated orchanged to the corresponding number of each of TM_ENT and VOBU_ENTobtained after the deletion (step ST116).

[0499] Then, video object information (VOBI) of VOB(S) next to VOB#n ismoved by one VOB (step ST118).

[0500] A space is created by the deletion of step ST116. The new VOBI ofstep ST118 is recorded in the created space (step ST120), where VOB type(VOB_TY), VOB recording time (VOB_REC_TM), sub-second information ofVOB_REC_TM (VOB_REC_TM_SUB), and movie VOB stream information number(M_VOB_STIN) are the same as those of VOB#n. VOB_V_S_PTM represents thestart PTM of this VOB. VOB_V_E_PTM (end PTM of this VOB) represents theoriginal VOB_V_E_PTM of the divided VOB.

[0501] Further, data of a group from “the TM_ENT and VOBU_ENT of thedivided VOBU including the start PTM of the determined area” to “theTM_ENT and VOBU_ENT of the last VOBU” are set at TMAPI (step ST120).

[0502] Still further, each number of the TM_ENT and VOBU_ENT of a timemap general information (TMAP_GI) is updated or changed to thecorresponding number obtained by the above setting at the TMAPI (stepST120).

[0503] The reference will be made to FIG. 46.

[0504] It is checked whether a division of the end VOB is necessary(step ST122).

[0505] If the division of the end VOB is not necessary (NO at stepST122), the process goes to step ST132 described hereinafter.

[0506] When the division of the end VOB is necessary (YES at stepST122), the process goes to step ST124 described hereinafter.

[0507] When the division of the end VOB is necessary (YES at stepST122), the VOB (VOB#k) to be divided (which is located at the lastportion) is determined (step ST124).

[0508] Then, start PTM of VOB#k (VOB_S_PTM), end PTM of VOB#k(VOB_E_PTM), and time map information (TMAPI) thereof are stored in theRAM or register of MPU 30 (step ST126).

[0509] At this time, the end PTM of the determined area is set atVOB_E_PTM (step ST126).

[0510] Further, the TM_ENT and the VOBU_ENT of VOBU next to VOBU of endPTM of the determined area are deleted, and the number of each of TM_ENTand VOBU_ENT of TMAP_GI are updated or changed to the correspondingnumber of each of TM_ENT and VOBU_ENT obtained after the deletion (stepST126).

[0511] Then, video object information (VOBI) of VOB(s) next to VOB#k ismoved by one VOB (step ST128).

[0512] A space is created by the deletion of step ST126. The new VOBI ofstep ST128 is recorded in the created space (step ST130), where VOB_TY,VOB_REC_TM, VOB_REC_TM_SUB, and M_VOB_STIN are the same as those ofVOB#k. VOB_V_S_PTM represents the start PTM of VOBU next to the PTM ofthe end of the determined area. VOB_V_E_PTM (end PTM of this VOB)represents the original VOB_V_E_PTM of the divided VOB.

[0513] Further, data of a group from “the TM_ENT and VOBU_ENT of theVOBU next to the VOBU of the end PTM of the divided area” to “the TM_ENTand VOBU_ENT of the last VOBU” are set at TMAPI (step ST130).

[0514] Still further, each number of the TM_ENT and VOBU_ENT of TMAP_GIis updated or changed to the corresponding number obtained by the abovesetting at the TMAPI (step ST130).

[0515] Then, within a movie AV file information general information(M_AVFI_GI), the number of search pointers (SRP_Ns) is increased by thenumber of VOBI caused by the division, and the value of search pointer(SRP) is updated or changed (step ST132).

[0516] Thus, the VOB number is updated or changed.

[0517] Thereafter, a flag of the temporary erase (TE) is set at VOBI(VOB_TY) of VOB in the determined area (step ST134).

[0518] The reference will be made to FIG. 47.

[0519] It is checked whether (any) VOB is divided (step ST136).

[0520] If no VOB is divided (NO at step ST136), the process goes to stepST158 described hereinafter.

[0521] When any VOB is divided (YES at step ST136), it is furtherchecked whether the divided VOB is the start VOB (step 138).

[0522] If the start VOB is not divided (NO at step ST138), the processgoes to step ST158.

[0523] When the start VOB is divided (YES at step ST138), it is stillfurther checked whether the divided point of the start VOB matches theboundary of related cells (step 140).

[0524] When the divided point matches the boundary of cells (or theboundary of VOBS) (YES at step ST140), no cell division (or VOBdivision) is necessary. Then, only movie VOBI search pointer numberM_VOBI_SRPN in movie cell general information M_C_GI of cells after thedivided point is updated or changed accordingly (step ST142).

[0525] Then, the process goes to step ST158.

[0526] If the divided point does not match the boundary of cells (or theboundary of VOBS) (NO at step ST140; see the vertically directed arrowsin the illustration of FIG. 49 or 50), then the cell (called CELL-N) tobe divided, located at the start or leading portion of the dividingarea, is determined (step ST144).

[0527] The end PTM of CELL-N (C_V_E_PTM) is updated or changed to theend PTM (E_PTM) of the divided VOB (step ST146).

[0528] When any entry point (EP) exists after the updated E_PTM, theentry point information (EPI) of the EP is stored, the EP is deletedfrom the current (or present) cell information (CI), and the number ofEPI (EPI_Ns) is updated so that the EPI_Ns is reduced by the number ofdeleted EP (step ST146).

[0529] Then, cell information (CI) of cell(s) next to CELL-N is moved byone CI (step ST148).

[0530] A space is created by the deletion of step ST146. The new CI ofstep ST148 is recorded in the created space (step ST150), where celltype (C_TY) is the same as that of CELL-N, the movie VOBI search pointernumber (M_VOBI_SRPN) of M_C_GI of VOB created by division is updated orchanged, the start PTM of the cell (C_V_S_PTM) and end PTM of the cell(C_V_E_PTM) are updated or changed to the start PTM (S_PTM) and end PTM(E_PTM) of VOB created by division, respectively, stored entry pointinformation (EPI) is added, and the number of EPI (EPI_Ns) is updated orchanged to the added number of EPI (step ST150).

[0531] The reference will be made to FIG. 48.

[0532] If the end VOB is not divided (NO at step ST158), the processgoes to step ST172.

[0533] When the end VOB is divided (YES at step ST158), it is checkedwhether the divided point of the end VOB matches the boundary of relatedcells (step 160).

[0534] When the divided point matches the boundary of cells (or theboundary of VOBS) (YES at step ST160), no cell division (or VOBdivision) is necessary. Then, only movie VOBI search pointer numberM_VOBI_SRPN in movie cell general information M_C_GI of cells after. thedivided point is updated or changed accordingly (step ST162).

[0535] Then, the process goes to step ST172.

[0536] If the divided point does not match the boundary of cells (or theboundary of VOBS) (NO at step ST160), then the cell (called CELL-M) tobe divided, located at the end or trailing portion of the dividing area,is determined (step ST164).

[0537] The end PTM of CELL-M (C_V_E_PTM) is updated or changed to theend PTM (E_PTM) of the divided VOB (step ST166).

[0538] When any entry point (EP) exists after the updated E_PTM, theentry point information (EPI) of the EP is stored, the EP is deletedfrom the current (or present) cell information (CI), and the number ofEPI (EPI_Ns) is updated so that the EPI_Ns is reduced by the number ofdeleted EP (step ST166).

[0539] Then, cell information (CI) of cell(s) next to CELL-M is moved byone CI (step ST168).

[0540] A space is created by the deletion of step ST166. The new CI ofstep ST168 is recorded in the created space (step ST170), where celltype (C_TY) is the same as that of CELL-M, the movie VOBI search pointernumber (M_VOBI_SRPN) of M_C_GI of VOB created by division is updated orchanged, the start PTM of the cell (C_V_S_PTM) and end PTM of the cell(C_V_E_PTM) are updated or changed to the start PTM (S_PTM) and end PTM(E_PTM) of VOB created by division, respectively, stored entry pointinformation (EPI) is added, and the number of EPI (EPI_Ns) is updated orchanged to the added number of EPI (step ST170).

[0541] Then, each M_VOBI_SRPN in M_C_GI of cells other than the dividedpoint is updated or changed (step ST172).

[0542] At this time, information pieces, such as the total number ofcells (CI_SRP_Ns) in PGC general information (PGC_GI), the number ofcells (C_Ns) in program information (PGI), the cell information searchpointer (CI_SRP), etc., are also updated or changed (step ST172).

[0543] Further, when user defined PGC information (UD_PGCI) exists,similar processing will be made with respect to UD_PGCI (step ST172).

[0544] Finally, the user may confirm whether or not the setting oftemporary erasion is completed (step ST174).

[0545] If the temporary erasion is not completed (NO at step ST174), theprocess returns to step ST100 of FIG. 45.

[0546] When the user depresses an end key or the like, the condition ofcompleting the temporary erasion setting is entered (YES at step ST174),and the operation of FIGS. 45-48 is finished.

[0547] The present invention is not limited to the aforementionedembodiment. Software that includes the processing sequences shown in therespective flow charts is recorded in advance on a recording medium(disc 10 shown in FIG. 1 or the like), and is read by a playbackapparatus (or a personal computer with a DVD-RAM drive) to automaticallyset up an environment for implementing the processes of the respectiveflow charts.

[0548] In other words, the present invention includes a case wherein themedium itself has information (software application) for implementingthe processes of the respective flow charts.

[0549] The characteristic features of the above-mentioned embodiment canbe summarized as follows.

[0550] A recording medium is constructed by a management area and dataarea, which divisionally records data in one or more sequences (programchains). Each sequence consists of one or more cells, and one cellconsists of one or more data units. Each data unit is recorded bypacking video and audio data to be played back within a predeterminedperiod of time in a plurality of packs. The management area(hierarchically) contains a management table for managing the sequences,a management table for managing the cells, and a management table formanaging the data units.

[0551] Note that one feature is that temporary erasion playback sequenceinformation (PGCI of trash PGC) is recorded in the management area.Another feature is that the temporary erasion playback sequenceinformation records an original PGC number and cell number of atemporary erased cell.

[0552] A recording/playback method and apparatus are characterized byhaving a cell erasion level setting means for appending erasion levelinformation to the cell management table. Also, the method and apparatusare characterized by having a cell division detection unit (a functionof MPU 30) for, when temporary erasion is designated in units of dataunits, checking if the designated data unit is present at a division ofa cell, a cell division unit (another function of MPU 30) for dividing acell when the cell is divided based on a signal from the detection unit,and an erasion level setting unit (still another function of MPU 30) forappending erasion level data to a cell corresponding to the designateddata unit.

[0553] The playback method and apparatus are further characterized byhaving an erasion level range designation unit (still another functionof MPU 30) for displaying time information corresponding to the playbacktime of a sequence, and designating an erasion level range using thetime information, and a video display unit (still another function ofMPU 30) for displaying video data of a data unit closest to a displaytime corresponding to the designated time position, so as to allow theuser to easily set (or cancel) the erasion level.

[0554] Furthermore, the method and apparatus are characterized by havingan erasion level designation unit (still another function of MPU 30) fordisplaying time information corresponding to the playback time of asequence, and designating an erasion prohibition range using the timeinformation, and a video display unit (still another function of MPU 30)for displaying the playback time corresponding to the designated timeposition, so as to allow the user to easily set (or cancel) the erasionlevel.

[0555] Moreover, the recording/playback method and apparatus arecharacterized by having a cell designation unit (still another functionof MPU 30) for designating a temporary erased area in units of cells,and a cell recovery unit (still another function of MPU 30) forrecovering a cell designated by the designation unit.

[0556] Further, the method and apparatus are characterized by having acell designation unit (still another function of MPU 30) for designatinga temporary erased area in units of cells, and a cell actual erasionunit (still another function of MPU 30) for actually erasing the celldesignated by the cell designation unit.

[0557] In addition, the method and apparatus for recording/playing backinformation on/from a recordable recording medium are characterized byhaving a cell arranging unit (still another function of MPU 30) forerasing a temporary erased cell when the remaining recordable spacebecomes smaller than a predetermined amount.

[0558] Also, the method and apparatus are characterized by having a PGCarranging unit (still another function of MPU 30) for erasing trash PGCafter the temporary erased cell has been erased.

[0559] The method and apparatus are also characterized by having a trashPGCI creation unit (still another function of MPU 30) for creatingsequence information which can be played back as a sequence that can beplayed back by joining temporary erased cells.

[0560] Furthermore, the method and apparatus are characterized by havinga recording unit for recording sequence information from the trash PGCIcreation unit.

[0561] Moreover, the method and apparatus are characterized by having atrash PGCI display unit for displaying sequence information which can beplayed back as a sequence that can be played back by joining temporaryerased cells.

[0562] To restate, according to the present invention, the erasion levelcan be designated (or canceled) in small units, thereby allowingflexible data management.

1. A digital movie information recording medium (10 in FIG. 1)comprising: a data area (DA in FIG. 17) for storing file data (e.g.,RTR_MOV.VRO in FIG. 20) containing digital movie information recorded ina predetermined recording unit; and a management area (DA21 in FIG. 17)for storing navigation data (RTR.IFO or RTR_VMG in FIG. 20) for managinginformation stored in said data area, wherein said management areacomprises: a first storage field (e.g. C_PBI in FIG. 12; M_VOBI in FIG.24) for storing an erasion level flag which sets a specific recordingunit (e.g., lower cells 3 and 4 in FIG. 39; lower VOB3 and VOB4 in FIG.49) in said data area in a temporarily erased state:
 2. A mediumaccording to claim 1, further comprising a second storage field (C_PBIin FIG. 16; M_VOBI in FIG. 24) for storing information (PGC_N, C_ID_N;M_VOBI_GI/VOB_TY/TE) of a recording field (PGC) to which the specificrecording unit set with the erasion level flag originally belongs,wherein recording contents of said first and second storage fields(C_PBI; M_VOBI) contain information (PGC_N, C_ID_N in FIG. 16; trash PGCinformation in PRM_TXTI in FIG. 33; M_VOBI_GI in FIG. 24) required forrecovering the specific recording unit (lower cells 3 and 4 in FIG. 39;lower VOB3 and VOB4 in FIG. 49) set in the temporarily erased state to astate before erasion.
 3. A medium according to claim 1 or 2, wherein thespecific recording unit (lower cells 3 and 4 in FIG. 39; lower VOB3 andVOB4 in FIG. 49) set in the temporarily erased state are allowed to beactually erased (step C10 in FIG. 40) on the basis of recording contentsof said first storage field (C_PBI in FIG. 12; M_VOBI in FIG. 24).
 4. Amedium according to any one of claims 1, 2, and 3, wherein saidmanagement area includes trash box information (trash PGC) containing atrash box flag (FIG. 15) which pertains to recording contents of saidfirst and second storage fields (C_PBI; M_VOBI), and whether or not thespecific recording unit set in the temporarily erased state is presentis determined (steps C3 to C7 in FIG. 40) on the basis of contents ofthe trash box flag.
 5. A recording method, which records information. ona digital information recording medium (10) having a data area (DA) forstoring file data (RTR_MOV.VRO) containing digital movie information ina predetermined recording unit, and a management area (DA21) for storingnavigation data (RTR.IFO or RTR_VMG) for managing information stored inthe data area, comprising the step of: storing an erasion level flagwhich sets a specific recording unit (lower cells 3 and 4 in FIG. 39) inthe data area in a temporarily erased state in a first storage field(C_PBI in FIG. 12; M_VOBI in FIG. 24) of the management area (step B21in FIG. 37).
 6. A method according to claim 5, further comprising thesteps of storing information (PGC_N, C_ID_N; M_VOBI_GI) of a recordingfield (PGC) to which the specific recording unit set with the erasionlevel flag originally belongs in a second storage field (C_PBI in FIG.16; M_VOBI in FIG. 24) of the management area (step B22 in FIG. 37); andrecovering the specific recording unit (lower cells 3 and 4 in FIG. 39;lower VOB3 and VOB4 in FIG. 49) set in the temporarily erased state to astate before erasion on the basis of recording contents of the first andsecond storage fields (C_PBI; M_VOBI) (step C9 in FIG. 40).
 7. A methodaccording to claim 5 or 6, further comprising the step of actuallyerasing the specific recording unit (lower cells 3 and 4 in FIG. 39;lower VOB3 and VOB4 in FIG. 49) set in the temporarily erased state onthe basis of recording contents of the first storage field (C_PBI inFIG. 12; M_VOBI in FIG. 24) (step C10 in FIG. 40).
 8. A method accordingto any one of claims 5, 6, and 7, further comprising the step ofcreating trash box information (trash PGC) containing a trash box flag(FIG. 15) which pertains to recording contents of the first and secondstorage fields (C_PBI; M_VOBI) (step B3 in FIG. 36).
 9. A playbackmethod, which extracts recording information from a digital informationrecording medium (10) having a data area (DA) for storing file data(RTR_MOV.VRO) containing digital movie information in a predeterminedrecording unit, and a management area (DA21) for storing navigation data(RTR.IFO or RTR_VMG) for managing information stored in the data area,comprising the steps of: extracting an erasion level flag which sets aspecific recording unit (lower cells 3 and 4 in FIG. 39; lower VOB3 andVOB4 in FIG. 49) in the data area in a temporarily erased state from apredetermined field (C_PBI in FIG. 12; M_VOBI in FIG. 24) of themanagement area (step E5 in FIG. 44); and skipping playback of thespecific recording unit (lower cells 3 and 4 in FIG. 39; lower VOB3 andVOB4 in FIG. 49) set with the erasion level flag when the erasion levelflag is set in the temporarily erased state (YES in step E10 in FIG.44).
 10. A method according to claim 9, further comprising: when thepredetermined field (C_PBI; M_VOBI) of the management area containstrash information (trash PGC) that pertains to the temporarily erasedstate of recording contents, the display step (steps C3 to C7 in FIG.40) of making a display that reveals contents of the specific recordingunit in the temporarily erased state on the basis of contents of thetrash box information (trash PGC).
 11. A method according to claim 10,further comprising the step of presenting a trash box mark indicatingthat information set in the temporarily erased state is recorded on themedium before the display step is executed (step C2 in FIG. 40).
 12. Arecording method for recording an object comprised of a set of cells,and management information used for playing back the object on arecording medium which has a data area for storing the object and amanagement area for storing the management information, comprising thesteps of: setting (B5-B10 in FIG. 36) an appending range of erasionlevel information for designating with respect to one or more specificcells of the object whether playback is permitted or inhibited; setting(B11-B20 in FIGS. 36-37) a divided cell, when a terminal portion of theerasion level information appending range does not match a cell unit ofa current cell, by dividing the current cell of the mismatch; andchanging (B21-B24 in FIG. 37) the management information for playingback the divided cell and current cell in accordance with contents ofthe cell division, and appending the erasion level information to themanagement information of the divided cell which belongs to the erasionlevel information appending range.
 13. A recording apparatus forrecording an object comprised of a set of cells, and managementinformation used for playing back the object on a recording medium whichhas a data area for storing the object and a management area for storingthe management information, comprising: erasion level appending settingmeans for setting an appending range of erasion level information fordesignating with respect to one or more specific cells of the objectwhether playback is permitted or inhibited; cell division means forsetting a divided cell, when a terminal portion of the erasion levelinformation appending range does not match a cell unit of a currentcell, by dividing the current cell of the mismatch; and new managementinformation re-creating means for re-creating the management informationfor playing back the divided cell and current cell in accordance withcontents of the cell division, and appending the erasion levelinformation to the management information of the divided cell whichbelongs to the erasion level information appending range.
 14. Anapparatus for playing back recording information from a recording mediumwhich has a data area that records an object comprised of a set ofcells, and a management area that records management information usedfor playing back the object, comprising: cell unit display means fordisplaying a desired object in a predetermined cell unit on the basis ofthe management information played back from the medium; erasion levelappending range setting means for setting an appending range of erasionlevel information for designating whether playback is permitted orprohibited, in a unit not larger than the cell unit displayed by saidcell unit display means; and means for, when the erasion levelinformation appending range set by said erasion level appending rangesetting means is determined and a current cell is consequently divided,displaying a cell unit of the object using a sequence of new dividedcell units.
 15. A recording method for recording an object (VOB) andmanagement information used for playing back the object on a recordingmedium which has a data area for storing the object and a managementarea for storing the management information, comprising the steps of:setting (ST100-ST110 in FIG. 45) an appending range (upper illustrationof VOB2, VOB3 in FIG. 49) of erasion level information (protect flag atST134 in FIG. 46) for designating with respect to one or more specificobjects (lower illustration of VOB3, VOB4 in FIG. 49) whether playbackis permitted or inhibited; setting (ST112-ST132 in FIGS. 45-46) adivided object, when a terminal portion of the erasion level informationappending range (upper illustration of VOB2-VOB3 in FIG. 49) does notmatch a unit of a current object (upper VOB2 or upper VOB3 in FIG. 49),by dividing the current object (upper VOB2 or upper VOB3 in FIG. 49) ofthe mismatch; and changing (ST130 in FIG. 46) the management information(VOBI) for playing back the divided object and current object inaccordance with contents of the object division, and appending (ST134 inFIG. 46) the erasion level information (protect flag) to the managementinformation (VOBI) of the divided object (lower VOB3 or lower VOB4 inFIG. 49) which belongs to the erasion level information appending range(lower VOB2-VOB5 in FIG. 49).
 16. An apparatus for recording and playingback video information from a recording medium, comprising: a temporaryerased portion specifying portion (MPU 30 in FIG. 34; E3-E7 in FIG. 44)for specifying a temporarily erased portion (CELL3-CELL4 in the lowerillustration of FIG. 12; or VOB3-VOB4 in the lower illustration of FIG.49); a temporary erased portion detecting portion (MPU 30 in FIG. 34;E10 in FIG. 44) for detecting only a unit of reproduction of thetemporarily erased portion (CELL3-CELL4 in the lower illustration ofFIG. 12; or VOB3-VOB4 in the lower illustration of FIG. 49) according tothe specifying of said temporary erased portion specifying portion; atemporary erased portion indicating portion (MPU 30 in FIG. 34; E11, E18in FIG. 44) for indicating said unit of reproduction of the temporarilyerased portion (CELL3-CELL4 in the lower illustration of FIG. 12; orVOB3-VOB4 in the lower illustration of FIG. 49), thereby said apparatusbeing able to reproduce the indicated unit of reproduction.